Chapter 7 and 8 chemistry

How are ionic and covalent bonds different?

Ionic bonds are bonds made between ionic compounds in which electrons are either gained or lost covalent bonds are made between molecular compounds in which electrons are shared

What is the electron configuration and dot diagram for anions?

1. HALIDE IONS: are the ions from chlorine or other halogens that gain electrons a) name given to the halogen family 2. nonmetals will have many valence electrons (usually 3 or more) 3. they will GAIN electrons to fill outer shell a) they add electrons to their diagrams 4. they are called ______-ide ions a) example: phospide ion

What is an anion

A NEGATIVE ION 1. has gained elections 2. NONMETALS CAN GAIN ELECTRONS a) nonmetals, which are located on the right side of the periodic table, easily gain electrons to attain a stable outer electron configuration b) nonmetals gain the number of electrons, that when added to their valence electrons, equal 8 c) in general, group 15 elements gain 3 electrons, group 16 elements gain 2, and group 17 elements gain 1 to achieve an octet 3. charge is written as a superscript on the right a) write elements symbol and its number and charge as a subscript 4. IF IT HAS GAINED ONE ELECTRON -IDE IS THE NEW ENDING a) ends in -ide for monoatomic ions 5. examples: a) F⁻¹ goes from fluorine to fluoride b) O⁻² goes from oxygen to oxide

What are molecular compounds? What are isolated atoms? What is the difference between a molecule and molecular compound

COMPOUNDS THAT ARE BONDED COVALENTLY (LIKE WATER AND CARBOND DIOXIDE) 1. Made of molecules a) do not contain metals just nonmetals 2. Made by joining NONMENTAL atoms together into molecules 3. 118 different elements 4. Millions of compounds from them 5. Naming is essential in chemistry a) noble gases such as He and Ne 6. ISOLATED ATOMS: monatomic (one atom ion), they consist of a single atoms a) noble gases are non reactive and do not form compounds with other elements b) noble gases are nonatomic, either don't react at all or do it in a laboratory setting c) this is because they have a full valence shell 7. MADE FROM ONLY NONMENTALS 8. Can be from one element (O₂): molecule or it can be made from a compound: (CO₂) (molecular compound 9. TEND TO HAVE RELATIVELY LOWER MELTING AND BOILING POINTS THAN IONIC COMPOUNDS 10. thus, molecular compounds tend to be GASES, OR LIQUIDS AT ROOM TEMPERATURE a) ionic compounds would be solids 11. consists of a MOLECULAR FORMULA

What are electron dot diagrams?

ELECTRON DOT DIAGRAMS ARE A WAY OF SHOWING AND KEEPING TRACK OF VALENCE ELECTRONS a) a type of diagram used to keep track of valence electrons 1. HOW TO WRITE THEM a) write the symbol, it represents the nucleus and the inner (core) electrons b) put one dot for each valence electron (8 maximum) c) f you have 8 electrons, you have a noble gas d) they don't pair up until they have to (hund's rule) e) put only 22 dots on each side f) doesn't matter what side you start on 2. electron dot structures are especially helpful when used to illustrate the formation of chemical bonds 3. valence electrons are represented by the dots

What is a bond? What are the types of bonds?

FORCES THAT HOLD GROUPS OF ATOMS TOGETHER AND MAKE THEM FUNCTION AS A UNIT a) chemical bonds can form by the attraction of another atom or by the attraction between positive ions and negative ions TYPES: 1. IONIC BONDS: TRANSFER OF ELECTRONS EITHER GAINED OR LOST a) the electrostatic force that holds oppositely charged particles together in an ionic compound b) if ionic bonds occur between metals and the nonmetal oxygen, oxide forms c) most other ionic compounds are called salts d) hold ionic compounds together 2. COVALENT BONDS: SHARING OF ELECTRONS, THE RESULTING PARTICLES IS CALLED A "MOLECULE" (the chemical bond that results from sharing valence electrons) a) covalent bonds hold molecular compounds together b) NONMETALS hold on to their valence electrons c) CONSISTS OF ONLY NONMETALS d) they can't gie away electrons to bond because it takes too much energy to give up all of the valence electrons but sharing takes less e) still want noble gas configuration f) THEY GET IT BY SHARING VALENCE ELECTRONS WITH EACH OTHER= COVALENT BONDING g) by sharing BOTH ATOMS get to count the electrons toward a gas configuration h) each are stable and unreactive and both get to count as a full octet 3. in a covalent bond, the shared electrons are considered to be part of the outer energy levels of both atoms involved a) covalent bonding generally can occur between elements that are near each other on the periodic table b) the majority of covalent bonds form between atoms of nonmetallic elements 4. The most stable arrangemnt of atoms in a covalent bond exists at some optimal distance between nuclei 5. unbonded or not shared electrons are known as lone pairs

What is a molecule? What is a diatomic molecule

MOLECULES: A NEUTRAL GROUP OF ATOMS JOINED TOGETHER BY COVALENT BONDS 1.smallest unit of a molecular compound is a molecule 2. a molecule has more than one of the same type of atom 3. a molecular compound have different types of elements 4. many elements in nature are in the from of molecules 5. for example, air contains oxygen molecules consisting of two oxygen atoms joined covalently a) called a DIATOMIC MOLECULE : two atoms of the same element joined together covalently

Determine which type of bond should be formed between the two atoms: Phosphorous and Silicon (electronegativity is 0.3)

Nonpolar covalent

What are cations?

POSITIVE IONS 1. formed by losing electrons 2. more protons than electrons 3. METALS CAN LOSE ELECTRONS 4. write the symbol in the same way as a anion a) has lost one electron so there is NO name change for POSITIVE ions b) it is just called a ________ ion 5. EXAMPLE: a) Ca²⁺ is a calcium ion b) K⁺¹ is a potassium ion

What valence electrons? What are core electrons?

VALENCE ELECTRONS ARE: the electrons responsible for the chemical properties of atoms, and are those in the outer energy levels 1. the s and p electrons in the outer energy levels a) the electrons in the s and p valence shells b) it depends on the highest occupied energy level for the element 2. CORE ELECTRON: those in the energy levels below a) inner electrons 3. d and f do not have any valence electrons 4. difference in reactivity of different elements is directly related to the valence electrons a) the difference in reactivity involves the octet- the stable arrangement of 8 valence electrons in the outer energy level b) unreactive noble gases have electron configurations that have a full outermost energy level c) this level is filled with two electrons for helium (1s²) and eight electrons for the other noble gases (ns²np⁶) d) elements tend to react to acquire the stable electrons structure of a noble gas

What are the names of these elements: a) Na¹⁺ b) Ca⁺² c) Al³⁺ d) Fe³⁺ e) Fe²⁺ f) Pb⁺² g) Li¹⁺ h) Cl¹⁻ i) N³⁻ j) Br¹⁻ k) O²⁻ l) Ga³⁺

a) Na¹⁺: sodium ion b) Ca⁺²: calcium ion c) Al³⁺: aluminium ion d) Fe³⁺: iron (III) ion e) Fe²⁺: iron (II) ion f) Pb⁺²: lead (II) ion (not a transition metal but it has two possible charges) g) Li¹⁺: lithium ion h) Cl¹⁻: chloride i) N³⁻: nitride j) Br¹⁻: bromide k) O²⁻: oxide l) Ga³⁺: gallium ion

What are the diatomic molecules found in nature?

a) all gases except for bromine and iodine b) always has 2 atoms of same element in nature when they form bonds together c) when looking these elements, you always need to double the mass d) they exist this way because the two atom molecules are more stable than the individual atoms 1. Br₂ 2. I₂ 3. N₂ 4. Cl₂ 5. H₂ 6. O₂ 7. F₂

Determine which type of bond should be formed between the two atoms: Cobalt and bromine (electronegativity is 1.0)

ionic

Determine which type of bond should be formed between the two atoms: cesium and oxide (electronegativity is 2.8)

ionic

Determine which type of bond should be formed between the two atoms: iron and carbon (electronegativity is 0.7)

ionic

Determine which type of bond should be formed between the two atoms: lithium and chloride (electronegativity is 2.0)

ionic

Determine which type of bond should be formed between the two atoms: potassium and nitrogen (electronegativity is 2.2)

ionic

Determine which type of bond should be formed between the two atoms: hydrogen and phosphorous (electronegativity is 0)

non polar covalent

Determine which type of bond should be formed between the two atoms: Silicon and fluorine (electronegativity is 2.2)

polar covalent

Determine which type of bond should be formed between the two atoms: arsenic and chloride (electronegativity is 1)

polar covalent

Determine which type of bond should be formed between the two atoms: germanium and selenium (electronegativity is 0.6)

polar covalent

What is a metallic bond

the attraction of a metallic cation for delocalized electrons 1. the electrons present in the outer energy levels of the bonding metallic atoms are not held by any specific atom and can move easily from one atom to the next 2. because they are free to move they are referred to as delocalized electrons a) when the atom's outer electrons move freely throughout the solid, a metallic cation is formed b) each such ion is bonded to all neighboring metal cations by the sea of valence electrons creating a metallic bond

What determines the properties of a compound

the chemical bonds in a compound determine many of its properties

What are some examples of covalent compounds?

1) molecular compound name: dihydrogen monoxide a) Formula: H₂O b) common name: water 2) molecular compound name: nitrogen trihydride a) formula: NH₃ b) common name: ammonia 3) molecular compound name: dinitrogen tetrahydride a) formula: N₂H₄ b) common name: hydrazine 4) molecular compound name: hydrochloric acid a) formula: HCl b) common name: muriatic acid 5) molecular compound name: 2-(acetyloxy) benzoic acid a) formula: C₉H₈O₄ b) common name: aspirin

What is an atom? What is an ion?

1. ATOMS ARE ELECTRICALLY NEUTRAL a) same number of protons 2. IONS ARE ATOMS OR GROUPS OF ATOMS WITH A CHARGE (POSITIVE OR NEGATIVE) a) different numbers of protons and electrons b) gain or lose electrons c) only electrons can move when ions form d) protons never move because that would change the type of atom

What are the attraction forces between molecules? Name the different types

1. Attractions between molecules are what makes solid and liquid molecular compounds possible a) holds it together to allow for solid and liquids to exist (other wise it would be a GAS) b) the differences in properties are a result of differences in attractive forces c) in a covalent compound, the covalent bonds between atoms in molecules are strong, but the attraction forces between molecules are relatively weak 2. the weakest are called VAN DER WAAL'S FORCES- THERE ARE TWO KINDS: a) dispersion forces b) dipole interactions 3. intermolecular forces vary in strength but are weaker than the bonds that join atoms in a molecule or ions in an ionic compound 4. DISPERSION FORCES: a) weakest of all b) caused by the motion on electrons c) hold all halogens together d) strength increases as number of electrons increases e) Halogen diatomic molecules experience major attraction to one another because of the dispersion forces A) few electrons form gases (like fluorine and chlorine) B) more electrons form liquids or solids (like bromine and iodine f) this is between non polar molecules 5. DIPOLE INTERACTIONS: a) occurs when polar molecules are attracted to each other b) dipole interactions happen in water and are not limited to it c) positive region of one molecule of attracts the negative region of another molecule d) slightly stronger than dispersion forces A) more common among polar compounds e) opposites attract to each other, but are not completely hooked like ionic solids A) not completely joined together f) this is between oppositely charged ends of two polar molecules

How do you name binary ionic compounds

1. Binary compounds-2 elements a) many ionic compounds are binary, which means that they contain only two different elements 2. Ionic: a cation and a anion a) binary ionic compounds contain a metallic cation and a nonmetallic anion 3. to write the names, just name the two ions a) in the chemical formula for any ionic compound, the symbol of the cation is always written first, followed by the symbol of the anion b) subscripts represent the number of ions of each element in an ionic compound c) if no subscript is written, it is assumed to be one 4. Easy with representative elements (which are Group A elements) 5. NaCl= Na⁺¹ Cl¹⁻ = sodium chloride 6. MgBr₂ = Mg²⁺Br¹⁻ = magnesium bromide 7. Do this when you are naming the metal and nonmental binary compound a) name both metal ion and nonmetal ion and change the name of the anion b) cation names don't change 8. The problem comes with transition metals a) transition metals have different charges 9. need to figure out their charges 10. The compound must be neutral (all ionic compounds are neutral) a) some number of positive and negative charges 11. use the anion to determine the charge of the positive ion 12. cations can have multiple charges and you won't know until you see what it bonds with (anion) 13. the prefixes used in a name indicate the exact number of each atom present in the molecule and determine the subscripts used in the formula

What are common commercial alloys, their composition, and their uses?

1. COMMON NAME: Alnico a) COMPOSITION: Fe 50%, Al 20%, Ni 20%, Co 10% b) USES: magnets 2. COMMON NAME: brass a) COMPOSITION: Cu 67-90%, Zn 1-25%, Sn 1-18% b) USES: plumbing, hardware, lighting 3. COMMON NAME: bronze a) COMPOSITION: Cu 70-95%, Zn 1-25%, Sn 1-18% b) USES: bearings, bells, medals 4. COMMON NAME: cast iron a) COMPOSITION: Fe 96-97%, C 3-4% b) USES: casting 5. COMMON NAME: gold, 10-carat a) COMPOSITION: Au 42%, Ag 12-20%, Cu 37/46% b) USES: jewelry 6. COMMON NAME: lead shot a) COMPOSITION: Pb 99.8%, As 0.2% b) USES: shotgun shells 7. COMMON NAME: Pewter a) COMPOSITION: Sn 70-95%, Sb 5-15%, Pb 0-15% b) USES: tableware 8. COMMON NAME: stainless steel a) COMPOSITION: Fe 73-79%, Cr 14-18%, Ni 7-9% b) USES: instruments, sinks 9. COMMON NAME: sterling silver a) COMPOSITION: Ag 92.5%, Cu 7.5% b) USES: tableware, jewelry

What is the difference between polar bonds and non polar covalent bonds?

1. Covalent bonding means shared electrons a) but they are not shared equally 2. electrons are pulled as a tug of war between the atoms nuclei a) covalent bonding is not equal sharing and pulling of electrons unequally creates a polar bond 3. NONPOLAR COVALENT BONDS: the bonds that result from the equal sharing of electrons such as in diatomic molecules 4. When two different atoms bond covalently, there is an UNEQUAL SHARING a) the more electronegative atom will have a stronger attraction and acquire a slightly negative charge b) the other atom will have a slightly positive charge because the electrons are further away c) THIS IS CALLED POLAR COVALENT BOND OR SIMPLY POLAR BOND 5. You can determine the electronegativity of a compound by subtracting the electronegativity of the larger atom with the smaller one 6. when there is a large difference in the electronegativity between bonded atoms, an electron is transferred from one atom to the other which results in bonding that is primarily ionic 7. Covalently bonded molecules are either polar or non polar and the type depends on the location and nature of the covalent bonds in the molecule 8. a distinguishing feature of non polar molecules is that they are not attracted by an electric field a) polar molecules are attracted by a electric because polar molecules are dipoles with partially charged ends and have an uneven electron density 9. polar molecules and ionic compounds are usually soluble in polar substances, but non polar molecules dissolve only in non polar substances

Why are some chemicals gases, some liquids, and some solids? What are network solids?

1. Depends on the type of bonding 2. NETWORK SOLIDS: solids in which all the atoms are covalently bonded to each other a) covalently bonded atoms are bonded at regularly bonded angles so break molecule apart means yo have to break all of the bond angles b) type of covalent compound c) THE STRONGEST TYPE OF COVALENT COMPOUND 3. melts at very high temperatures, or not melting at all 4. Diamond does not really melt, but vaporizes to a gas at 3500°C and beyond 5. SiC used in grinding to decrease friction between melt parts, has a meting point about 2700°C a) reason they can hold friction b) angles determine strength and the more angles there are, the more structures which give it properties similar to ionic bonds

What are the properties of metals

1. Different than ionic compounds a) metals are not ionic, but share several properties with ionic compounds b) the bonding in both metals and ionic compounds are based on the attraction of particles with unlike charges c) metals often form lattice in the solid state that are similar to the ionic crystal lattice with 8 to 12 metal atoms closely surrounding each metal atom 2. they are a SEA OF ELECTRONS a) electrons are free to move through the solid b) metals always have at least one valence electron, but do not share these valence electrons with neighboring atoms or lose their valence electrons c) instead the outer energy levels of the metal atoms overlap d) this is called the ELECTRON SEA MODEL: proposes that all the metal atoms in a metallic solid contribute their valence electrons to form a "sea" of electrons which surrounds the metal cations in the lattice 3. metals conduct electricity a) the movement of mobile electrons around positive metallic cations makes metals good conductors b) the delocalized electrons in a material that does not contain mobile electrons c) mobile electrons easily move as part of an electric current when an electric potential is applied to a metal d) these same delocalized electrons interact with light, absorbing and releasing photons, thereby creating the property of luster in metals 4. Because they are a sea of electrons they are MALLEABLE a) hammered into shape (can bend) b) mobile electrons allow atoms to slide by sort of like ball bearings in oil c) when applied by force, the electrons slide and allow for them to be shaped 5. They are also ductile a) can be drawn into wires 6. Both malleability and ductility explain in terms of MOBILITY of the valence electrons a) metals are generally durable b) although metallic cations are mobile in a metal, they are strongly attracted to the electron surrounding them and are not easily removed from the metal 7. electrons are free to move from one atom to the next 8. the melting points of metals vary greatly a) in general, metals have moderately high melting points and high boiling points b) the melting points are not as extreme as the boiling points because the cations and electrons are mobile in a metal c) it does not take an extreme amount of energy for them to be able to move past each other d) however, during boiling, atoms must be separated from the group of cations and electrons which requires much more energy 9. the mobile electrons in transition metals consist not only of the two outer s electrons but also of the inner d electrons a) as the number of delocalized electrons increases, so do the properties of harness and strength

What is the electron configuration, outer energy level, # of valence electrons, orbital notation of last sublevel filled, and electron dot diagram for this element: lithium

1. Electron configuration: 1s²2s² 2. outer energy level: 2 3. # of valence electrons: 1 4. Orbital notation of last sublevel filled: s² 5. electron dot diagram: Li with 1 dot

What is the electron configuration, outer energy level, # of valence electrons, orbital notation of last sublevel filled, and electron dot diagram for this element: magnesium

1. Electron configuration: 1s²2s²2p⁶3s² 2. outer energy level: 3 3. # of valence electrons: 2 4. Orbital notation of last sublevel filled: 3s² 5. electron dot diagram: Mg with two dots around it not on the same side

What is the electron configuration, outer energy level, # of valence electrons, orbital notation of last sublevel filled, and electron dot diagram for this element: chlorine

1. Electron configuration: 1s²2s²2p⁶3s²3p⁵ 2. outer energy level: 3 3. # of valence electrons: 7 4. Orbital notation of last sublevel filled: 3s² 5. electron dot diagram: Cl with 7 dots, two on every side and one on one side

What is the electron configuration, outer energy level, # of valence electrons, orbital notation of last sublevel filled, and electron dot diagram for this element: zinc

1. Electron configuration: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰ 2. outer energy level: 4 3. # of valence electrons: 2 4. Orbital notation of last sublevel filled: 3d¹⁰ 5. electron dot diagram: Zn with two dots on either side

What is the electron configuration, outer energy level, # of valence electrons, orbital notation of last sublevel filled, and electron dot diagram for this element: arsenic

1. Electron configuration: [Ar] 4s²3d¹⁰4p³ 2. outer energy level: 4 3. # of valence electrons: 5 4. Orbital notation of last sublevel filled: 3d¹⁰ 5. electron dot diagram: As with 5 dots (two on the same side and three on different sides)

What is the electron configuration, outer energy level, # of valence electrons, orbital notation of last sublevel filled, and electron dot diagram for this element: nickel

1. Electron configuration: [Ar] 4s²3d⁸ 2. outer energy level: 4 3. # of valence electrons: 2 4. Orbital notation of last sublevel filled: 4s² 5. electron dot diagram: Ni with two dots on either side

Explain how each group of nonmetals reacts with single bonds

1. GROUP 17 AND SINGLE BONDS: a) the halogens- the group 17 elements such as fluorine have seven valence electrons b) to form an octet, one more electron is needed c) therefore, atoms of group 17 elements form single covalent bonds with atoms of other nonmetals such as carbon d) atoms of some group 17 elements form covalent bonds with identical atoms 2. GROUP 16 AND SINGLE BONDS: a) an atom of a group 16 element can share two electrons and can form two covalent bonds 3. GROUP 15 AND SINGLE BONDS: a) group 15 elements form covalent bond with atoms of nonmetals b) an example is nitrogen which forms similar compounds with atoms of group 117 elements, such as nitrogen trifluoride (NF₃), nitrogen trichloride (NCl₃), and nitrogen tribromide (NBr₃) c) each atom of these group 17 elements and the nitrogen atom share an electron pair 4. GROUP 14 AND SINGLE BONDS: a) atoms of group 14 elements form four covalent bonds b) an example, carbon, can also form single covalent bonds with other nonmetals atoms including those in group 17 c) example: a methane molecule (CH₄) forms when one carbon atom bonds with four hydrogen atoms d) with four valence electrons, carbon needs four more electrons for a noble gas configuration e) therefore, when carbon bonds with other atoms, it forms four bonds f) because a hydrogen atom has one valence electron, it take four hydrogen atoms to provide he four electrons needed by a carbon atom

What is ionic bonding?

1. anions and cations are held together by opposite charges 2. ionic compounds are called SALTS a) most common are ones bonding with halogens 3. SIMPLEST RATIO OF ELEMENTS IN AN IONIC COMPOUND IS CALLED THE FORMULA UNIT a) the chemical formula for an ionic compound 4. The bond is formed through THE TRANSFER OF ELECTRONS 5. electrons are transferred to ACHIEVE NOBLE GAS CONFIGURATION 6. EXAMPLE: NaCl a) the metal (sodium) tends to lose its one electron from the outer level b) takes less energy to give up 1 than to gain 7 c) the nonmetal (chlorine) needs to gain one more to fill its outer level and will accept the one electron that sodium is going to lose d) remember that no dots are shown at this point for the cation 7. EXAMPLE: combining calcium and phosphorus a) all the electrons must be accounted for, and each atom will have a noble gas configuration (which is stable) b) just 2 won't work c) a neutral charge over all is needed d) the formula unit is Ca₃P₂ e) this is a CHEMICAL FORMULA which shows the KINDS and NUMBERS OF ATOMS in the smallest representative particle of the substance

What are the properties of ionic compounds

1. Ionic bonds produce unique physical structures, unlike those of other compounds a) the physical structures of ionic compounds also contribute to their physical properties b) these properties have been used in many applications 2. CYSTALLINE SOLIDS: A REGULAR REPEATING ARRANGEMENT OF IONS IN THE SOLID a) there is a highly organized nature of an ionic crystal with consistent spacing of the ions and the uniform pattern formed by them 3. Ions are strongly bonded together a) structure is rigid b) high melting points 4.Melting point, boiling point, and hardness are physical properties of mater that depend on how strongly the particles that make up the matter are attracted to one another 5. Conducting electricity means allowing charges to move a) depends on the availability of freely moving charged particles b) ions are charged particles so whether they are free to move determines whether an ionic compound conducts electricity 6. in a solid, the ions are locked in place a) locked into fixed positions by strong attractive forces 7. ionic solids are insulators (do not conduct electricity) 8. when MELTED, the ions can move around a) melted ionic compounds conduct b) NaCl must get to about 800°C to melt c) difficult to get the ionic compounds to melt in order to conduct electricity d) both ionic compounds in solution and in the liquid state are excellent conductors of electricity e) electrolyte: an ionic compound whose aqueous solution conducts an electric current 9. DISSOLVED IN WATER: they also conduct electricity (free to move in aqueous solutions) a) easier to do cause ionic solids have a high melting point 10. IONIC SOLIDS ARE BRITTLE a) ionic solids are also hard, rigid brittle solids due to the strong attractive forces that hold the ions in place b) when an external force is applied to the solid-a force strong enough to overcome the attractive forces holding the ions in position within the solid-the solid cracks or breaks apart c) the solid breaks apart because the applied force repositions the like charged ions next to each other' the resulting repulsive force breaks apart the solid 11. STRONG REPULSION breaks a crystal a part due to similar ions being next to each other 12. Physical structure: a) in an ionic compound, large numbers of positive ions and negative ions exist together in a ratio determined by the number of electrons transferred from the metal atom to the nonmetal atom b) these ions are packed into a regular repeating pattern that balances the forces of attraction and repulsion between the ions 13. the strong attractions among the positive ions and the negative ions in an ionic compound result in the formation of a crystal lattice a) crystal lattice: a three dimensional geometric arrangement of particles b) in a crystal lattice, each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ions c) ionic crystals vary in shape due to the sizes and relative numbers of the ions bonded d) many ionic crystals have brilliant colors due to the presence of transition metals in the crystal lattice 14. Because ionic bonds are relatively strong, ionic crystals require a large amount of energy to be broken apart and thus, ionic crystals have high melting points and high boiling points

What are the properties of a molecular compound? How do you name molecular compounds

1. Low melting and boiling points 2. usually gas or liquid 3. composed of two or more nonmetals 4. Ex: O₂, O₃, H₂O 5. There are too many compounds to remember the names of them all a) because chemists around the world need to be able to communicate with one another, they have developed a set of rules for naming compounds b) using this standardized naming system, you can write a chemical formula from a compound's name and name a compound given its chemical formula 6. compounds are made of two or more elements a) electrons are exchanged or shred 7. Put together atoms a) when naming elements, you use prefixes or abbreviations to show it is a compound 8. name should tell us how many and what type of atoms a) prefix: how many b) ending: what type

What is a molecular formula? How do you name molecular compounds?

1. MOLECULAR COMPOUNDS CONSISTS OF MOLECULAR FORMULA: SHOWS HOW MANY ATOMS OF EACH ELEMENT A MOLECULAR CONTAINS 2. uses prefixes to tell you the number a) ionic compounds do not use prefixes b) one way of showing if it is ionic or molecular compounds c) ex: sodium chloride (ionic compound) vs carbon monoxide (molecular compound) HOW IT IS NAMED: 3. the FIRST ELEMENT written in the formula is always written FIRST USING THE ELEMENT NAME 4. THE SECOND ELEMENT is named using the root of the element and the SUFFIX "-IDE" 5. PREFIXES are used to indicate the number of atoms of each type that are present in the compound 6. EXCEPTION: do not use the prefix mono-for the first element 7. drop the final letter of the prefix when the element's name begins with a vowel (AO OR OO) 8. the formula for water is written as H₂O a) subscripts always follow the element that the are motfying b) the SUBSCRIPT 2 behind hydrogen means there are 2 atoms of hydrogen; if there is only one atom the subscript is omitted c) molecular formulas do not tell any information about the structure (the arrangement of the various atoms) d) don't tell us about the bonds, you need the Lewis Diagrams to get it

What are the common prefixes used in covalent compounds

1. MONO- one atom 2. DI-: two atoms 3. TRI-: three atoms 4. TETRA-: four atoms 5. PENTA-: five atoms 6. HEXA-: six atoms 7. HEPTA-: seven atoms 8. OCTA-: eight atoms 9. NONA-: nine atoms 10. DECA-: ten atoms CAN TELL BY THE SUBSCRIPT ON THE SYMBOL

What are the two types of compounds? What is the difference between the two types of compounds

1. Molecular Compounds a) SMALLEST PIECE: molecule b) TYPES OF ELEMENTS: nonmetals c) STATE: solid, liquid, or gas d) MELTING POINT: low, below 300°C 2. Ionic Compounds a) SMALLEST PIECE: formula unit b) TYPES OF ELEMENTS: metal and nonmetals c) STATE: solid d) MELTING POINT: high, above 300°C

How do electronegative values help us to determine the polarity of a bond?

1. The polarity of a bond is equal to the difference of the higher and lower values of electronegativity in a compound. 2. It helps to determine if the bond is polar covalent bond, non polar covalent bond or ionic bond 3. electronegativity increases when you go left to right across a period and decreases when you go top to bottom down a group SCALE: 1. Nonpolar covalent bond: 0.0=0.4 2. Polar covalent bond: 0.4-1.7 3. Ionic bond: 1.7-4.0 4. DON'T FORGET TO CHECK TO SEE IF THE ELEMENTS ARE EITHER BOTH NONMETALS (COVALENT BOND) OR EITHER A NONMETAL AND A METAL (IONIC) a) this will mean that they are either polar covalent or ionic regardless of their electronegativity value 5. bonding is not often clearly ionic or covalent a) an electronegativity difference of 1.70 is considered 50% covalent and 50% ionic a) as the difference in electronegativity increases,es the bond becomes more ionic in character b) it is sometimes inconsistent with experimental observations of two nonmetals bonding together

What are stable electron configurations?

1. all atoms react to try and achieve a noble gas configuration 2. noble gases have 2s and 6p electrons 3. 8 valence electrons means it is already stable 4. this is the octet rule (8 in the outer level is particularly stable) a) every element wants 8 electrons which is the purpose of forming compounds

What is the significance of water's bonds?

1. each hydrogen has 1 valence electron 2. each hydrogen wants 1 more to fill its valence shell 3. the oxygen has 6 valence electrons and wants 2 more 4. they share to make each other complete a) oxygen has a full octet b) hydrogen has 2 electrons which fills up its shell c) each hydrogen gives 1 (there is 2 hydrogen atoms in total) 5. a second hydrogen attaches 6. every atom has a full energy level 7. THERE ARE TWO "UNSHARED" PAIRS OF ELECTRONS a) these are very important because they are going to attract nearby hydrogen atoms that are not a part of the regular bonds b) it is not going to bond to the oxygen atom, but instead it is going to attract electrons without forming a bond- THIS IS CALLED HYDROGEN BONDING (puling another hydrogen atom to the already made water molecule) c) this is based on the electronegativity of the oxygen atom

What is the charge on ions?

1. for most of the group A elements, the periodic table can tell what kind of ions they will form from the location: MONATOMIC IONS a) the charge of a monatomic ion is equal to its oxidation number or oxidation state b) most transition metals and group 13 and 14 metals have more than one possible ionic charge c) the oxidation number of an element in an ionic compound equals the number of electrons transferred from the atom to form the ion 2. elements in the SAME GROUP have SIMILAR PROPERTIES 3. INCLUDING THE CHARGE WHEN THEY ARE IONS (see periodic table for charges) 4. GROUP 4A AND 8A do not usually form ions (in fact, group 8A rarely form compounds) 5. Group 4A: Si, Ge, C: don't form compounds (covelent bonds) a) Sn and Pb have different charges 6. many transition metals have more than ONE COMMON IONIC CHARGE

What are things to look for when dealing with polyatomic ions?

1. if cations have parenthesis, the number in parenthesis is their charge a) with transition metals, it is the roman numbers 2. if anions end in -ide, they are probably monoatomic ions and are off the periodic table 3. if anion ends in -ate or -ite, it is polyatomic a) -ate endings have 1 more O atom than -ite endings

What are the common names for some molecule compounds

1. many ionic compounds have common names in addition to their scientific ones a) for example baking soda is sodium hydrogen carbonate and common table salt is sodium chloride 2. many bianry molecular compounds such as nitrous oxide and water were discovered and given common names long before the present day naming system was developed a) other binary covalent compounds that are generally known by their common names rather than their scientific names are ammonia (NH₃) hydrazine (N₂H₄), and nitric oxide (NO)

How do electron dot diagrams work for cations? What is the exception? What is a pseud-noble gas configuration?

1. metals will have few valence electrons (usually 3 or less) a) they give away electrons because it takes less energy to give away there electrons than it does to gain 5 or 7 2. Metals will have few valence electrons 3. Metals will lose the valence electrons a) forming positive ions b) there is no dots shown on the electron configuration of a cation after they give them away, just the charge c) metals atoms are reactive because they lose valence electrons easily d) the group 1 and 2 metals are the most reactive metals on the periodic table e) some group 13 atoms also form ions 4. for TRANSITION METALS: a) they take valence electrons from the valence shell s first because valence electrons are not found in the d shell b) for this reason, transition metals can form a variety of charged cations c) they lose electrons from valence shell s first and then can lose some from the d subshell d) Transition metals have an outer energy level of ns² a) going from left to right across a period, atoms of each element fill an inner d sublevel e) when forming positive ions, transition metals commonly lose their two valence electrons, forming 2+ ions f) however it is also possible for d electrons to be lost g) thus, transition metals also commonly form ions of 3+ or greater depending on the number of d electrons in the electron structure 5. transition metals do not follow the same rules as the transition elements a) write there name with a roman numeral so you know what the charge is b) example: scandium (III) ion 6. EXCEPTION: SILVER: a) predicted configuration is 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d⁹ b) it's actual configuration ends in 5s¹4d¹⁰ because 5s²4d⁹ is an unstable c) for this reason, silver can lose any more than one electron and charges of 3 or greater are uncommon d) the d-subshell is full, so it only has 1 charge e) transition metals normally have more than 1 charge but silver doesn't because it's highest valence shell is 5s¹ f) it takes its valence electron from 5s and it can't have any more charges because 4d is full 7. YOU HAVE TO LOOK AT THE ANION TO FIND THE CHARGE FOR THE TRANSITION ELEMENT 8. SILVER DID THE BEST JOB IT COULD BUT IT DID NOT ACHIEVE TRUE NOBLE GAS CONFIGURATION a) instead it is called a "PSEUDO-NOBLE GAS CONFIGURATION": not actual noble gas configuration because instead of filling up s or p, it makes sure d is full so it is stable b) they will always be cations c) although the formation of an octet is the most stable electron configuration, other electron configurations can also provide some stability d) for example, elements in groups 11-14 lose electrons for form an outer energy level containing full s, p, and d sublevels e) these relatively stable electron arrangements are refered to as pseudo-noble gas configurations

Summarize how you name an ionic compound

1. name the cation followed by the anion. Remember that the cation is always written first in the formula 2. For monatomic cations, use the element name 3. for monatomic anion,s use the root of the element name plus the suffix -ide 4. to distinguish between multiple oxidation numbers of the same elements, the name of the chemical formula must indicate the oxidation number of the cation a) the oxidation number is written as a Roman numeral in parenthess after the name of the cation b) this rule applies to the transition metals and metals on the right side of the periodic table which often have more than one oxidation number c) it does not apply to group 1 and group 2 cations as they have only one oxidation number 5. When the compound contains a polyatomic ion, simply use the name of the polyatomic ion in place of the anion or cation

What is the octet rule? What are the exceptions to the octet rule?

1. noble gases are unreactive in chemical reactions 2. in 1916, GILBERT LEWIS used this fact to explain why atoms form certain kinds of ions and molecules 3. THE OCTET RULE: IN FORMING COMPOUNDS, ATOMS TEND TO ACHIEVE A NOBLE GAS CONFIGURATION; 8 IN THE OUTER LEVEL IS STABLE a) each noble gas (except He) has 8 electrons in the outer level b) elements form compounds for this reason- to achieve noble gas configuration according to the Octet Rule EXCEPTIONS: 3. for some molecules, it is impossible to satisfy the octet rule a) usually when there is an ODD NUMBER OF VALENCE ELECTRONS b) it is impossible to complete octet rule even when it is stable c) NO₂ has 17 valence electrons, because the N has 5 and contributes 6 d) It is impossible to satisfy octet rule, yet the stable molecule does exist 4. Another exception: Boron (has 3 valence electrons) a) boron trifluoride-one of the fluorides might be able to make a coordinate covalent bond to fulfill the boron A) one fluorine might fill up boron but not all 3 B) this is the same thing with chlorine b) but fluorine has the highest electronegativity of any element, this coordinate bond does not form c) some elements (phosphorus and sulfur) expand the octet rule to include 10 or 12 electrons (PCl₅ vs PCl₃) d) expand how many electrons they need to be stable A) an expanded octet can be explained by considering the d orbitals that occur in the energy levels of elements in period three or higher B) when you draw the lewis structures for these compounds, either extra lone pairs are added to the central atom or more than four bonding atoms are present in the molecule

What is are polar molecules?

1. only partial charges in bond polarity much lass than a true 1+ or 1- as in an ionic bonds a) the bonds are not completely positive or negative 2. the positive and minus signs with the lower case DELTA (δ⁺ or δ⁻) denote partial charges a) can be shown as either an arrow pointing towards the more electronegative atom or as a positive and negative delta symbol over the correct bond 3. A polar bond tends to make the entire molecule POLAR a) it has "AREAS OF DIFFERENCE" b) HCl has polar bonds, thus is a polar molecule c) a molecule that has two poles is called DIPOLE, like HCl A) this is when it is positive and negative 4. when polar molecules are placed between oppositely charged plates, they tend to become ORIENTED with respect to the positive and negative plates a) helps you to figure out which is which 5. a polar covalent bond is similar to a tug of war a) when a polar bond forms, the shared electron pair or pairs are pulled toward one of the atoms b) thus the electrons spend more time around that atom than the other atom c) this results in partial charges at the ends of the bond

What are chemical formulas?What is a molecular formula?

1. shows the kind and number of atoms in the smallest piece of a substance a) show how many there are, what kind, and the way they combine together 2. MOLECULAR FORMULA: UMBER AND KIDS OF ATOMS IN A MOLECULE a) tell what bond is formed and what it looks like b) for molecular compounds c) examples: CO₂, C₆H₁₂O₆ d) can tell how they bond together by how many electrons they need to get full valence shells

What is the smallest unit in an element, molecular compound, and ionic compound

1. smallest piece in an element: atom 2. smallest piece in a molecular compound: molecule 3. smallest piece in an ionic compound: formula unit 4. all of of the smallest units for each thing have the same properties and characteristics of that substance

What are the exceptions when it comes to naming ions?

1. some of the transition metals have only one ionic charge. not not use roman numerals for these: a) Silver is always 1+ (Ag⁺¹) b) Cadmium and Zinc are always 2+ (Cd²⁺ and Zn²⁺) 2. Lead (Pb) and tin (Sn) are not transition metals but have multiple charges so roman numerals must be used a) Pb (II or IV) b) Sn (II or IV)

What are the different ways to represent elements?

1. the molecular formula a) shows how many atoms of each element are present b) shows the element symbols and numerical subscripts c) tells you the type and number of each atom in a molecule b) ex: ammonia is NH₃ 2. the structural formula: a) also shows the arrangement of these atoms b) shows if it is single, double or triple bond c) doesn't show spaces, but shows the bonds d) ex: H₋O₋H e) uses letter symbols and bonds to show relative positions of atoms f) you can predict the structural formula for many molecules by drawing the Lewis structure g) more involved structures are needed to help you determine the shapes of molecules 3. The ball and stick model a) the best because it shows a 3-dimensional arrangement b) shows spaces between bonds, the bond lengths and type of bonds c) atoms of each specific element are represented by spheres of a representative color which are used for identifying the atoms if the chemical symbol of the element is not present

How does H₂ form?

1. the nuclei repel each other since they both have a positive charge, and like charges repel a) electrons of each atom will repel each other b) each opposite charge will attract each other c) this is particularly the case for diatomic molecules of atoms of the same element 2. electrons will attract equally to nuclei and nuclei will hold on with same force 3. they SHARE the electrons and this is called a COVALENT BOND AND INVOLVES ONLY NONMETALS

What is electronegativity and how does it relate to the atom's bond character

1. the type of bond formed during a reaction is related to each atom's attraction for electron a) the scale of electronegativity allows scientists to evaluate the electron affinity of specific atoms in a compound b) it indicates the relative ability of an atom to attract electrons in a chemical bond 2. Fluorine has the greatest electronegativity with 4.0 and francium has the least with 0.7 3. noble gases do not generally form compounds so the individual electronegativity values for helium, neon and argon are not listed but the largest noble gases like xenon sometimes bond with highly electronegative atoms like fluorine

What are ternary ionic compounds? How do you write the formula?

1. these will have polyatomic ions 2. at least 3 elements 3. polyatomic ions are combining with metals and nonmetals 4. must keep the entire polyatomic ion in tact when compounding with elements a) if there is a need for another subscript, put it in parenthesis 5. Example: LiCN: lithium cyanide, NaNO₃: sodium nitrate, (NH₄)₂O: amuniom oxide 6. The charges have to add up to zero 7. get charges on pieces a) cations from the name and location on the periodic table b) anions from the table or polyatomic ion chart 8. balance the charge by adding subscripts a) can't change subscripts or you change the ion 9. put polyatomics in parenthesis 10. Can use the criss-cross method a) charge becomes subscript for the other ion or some multiple of that number b) example: Calcium chloride: A) Ca²⁺ B) Cl¹⁻ C) Ca²⁺Cl¹⁻ would have a 1+ charge so you need another Cl₋¹ D) Ca⁺²Cl₂⁻¹

Why do atoms bond?

1. understanding the bonding in compounds is essential to developing new chemicals and technologies a) all noble gases have stable electron arrangements b) this stable arrangement consists of a full outer energy level and has lower potential energy than other electron arrangements c) because of their stable configurations, noble gases seldom form compounds 2. the stability of an atom, ion, or compound is related to its energy; that is, lower energy states are more stable a) metals and nonmetals can gain stability by transferring (gaining or losing) electrons to form ions b) the resulting ions have stable noble-gas electron configurations

What are alloys? Why use alloys? What are the types of alloys?

1. we use lots of metals every day but few are PURE metals 2. ALLOYS: MIXTURES OF 2 OR MORE ELEMENTS AT LEAST 1 IS A METAL a) a mixture of elements that has metallic properties b) a non pure metal c) due to the nature of metallic bonds, it is relatively easy to introduce other elements into the metallic crystal forming an alloy 3. made by melting a mixture of the ingredients then cooling them 4. Brass: an alloy for Cu and Zn 5. Bronze: an alloy of Cu and Sn 6. Properties are often SUPERIOR to the pure element a) sterling silver (92.5% Ag, 7.5% Cu) is harder and more durable than pure Ag, but still soft enough to make jewelry and tableware b) steels are very important alloys: made of iron and carbon A) corrosion resistant, ductility, hardness, toughness, cost c) "AMALGAM": dental uses, contains Hg 7. alloys/other metallic compounds do not have to balance charges since the electrons are constantly bouncing in and out 8. because of their unique blend of properties, alloys have a wide range of commercial applications 9. the properties of alloys differ somewhat from the properties of the elements they contain a) some alloys vary in properties depending on how they are manufactured b) in the case of some metals, different properties can result based on heating and cooling

What is a single covalent bond? What are multiple bonds and define them?

A SINGLE COVALENT BOND IS A SHARING OF TWO VALENCE ELECTRONS 1. only nonmentals and hydrogen 2. different from an ionic bond because they actually form molecules 3. two specific atoms are joined 4. in an ionic solid, YOU CAN'T TELL WHAT atom the electrons moved to for from 5. Sometimes atoms share MORE THAN ONE PAIR OF VALENCE ELECTRONS a) in some molecules, atoms have noble gas configurations when they share more than one pair of electrons with one or more atoms b) sharing multiple pairs of electrons forms multiple covalent bonds c) a double covalent bond and a triple covalent bond are examples of multiple bonds d) carbon, nitrogen, oxygen, and sulfur atoms often form multiple bonds with other nonmetals e) the number of valence electrons needed to form an octet equals the number of covalent bonds that can form (way to tell if two atoms will form a multiple bond) 6. a DOUBLE BOND is when atoms share 2 pairs of electrons (4 total) a) symbol: = b) a double bond forms when each element shares two electrons; a total of two pairs of electrons are shared between the two atoms 7. a TRIPLE BOND is when atoms share 3 pairs of electrons (6 total) a) symbol: - b) diatomic nitrogen (N₂) molecules contain a triple covalent bond c) each nitrogen atom shares three electron pairs, forming a triple bond with the other nitrogen atom 8. the shared electron pair is often referred to as the bonding pair

What are the names for the following formulas? What kind of bond are these? a) N₂O b) NO₂ c) Cl₂O₇ d) CBr₄ e) CO₂ f) BaCl₂ g) P₄S₅ h) O₂ i) SeF₆ j) Si₂Br₆ k) SCl₄ l) CH₄ m) B₂Si n) NF₃

ALL ARE COVALENT COMPOUNDS UNLESS OTHERWISE STATED a) N₂O: dinitrogen monoxide b) NO₂: nitrogen dioxide c) Cl₂O₇: dichlorine heptoxide d) CBr₄: carbon tetrabromide e) CO₂: carbon dioxide f) BaCl₂: barium chloride A) IONIC COMPOUND g) P₄S₅: tetraphosphorus pentasulfide h) O₂: dioxide A) common name is oxygen gas i) SeF₆: selenium hexafluoride j) Si₂Br₆: disilicon hexabromide k) SCl₄: sulfur tetrachloride l) CH₄: carbon tetrahydride A) common name: methan m) B₂Si: diboron monosicide n) NF₃: nitrogen trifluoride

What is the formula for each of the elements? What type of bond are they? a) diphosphorus pentoxide b) tetraiodine monoxide c) sulfur hexafluoride d) nitrogen trioxide e) carbon tetrahydride f) phosphorus trifluoride g) aluminum chloride h) antimony tribromide i) hexaboron silicide j) chlorine dioxide k) hydrogen iodide l) iodine pentafluoride m) dinitrogen trioxide n) ammonia o) phosphorus triiodide

ALL ARE COVALENT COMPOUNDS UNLESS OTHERWISE STATED a) diphosphorus pentoxide: P₂O₅ b) tetraiodine monoxide: I₄O₉ c) sulfur hexafluoride: SF₆ d) nitrogen trioxide: NO₃ e) carbon tetrahydride: CH₄ f) phosphorus trifluoride: PF₃ g) aluminum chloride: AlCl₃ A) IONIC COMPOUND h) antimony tribromide: SbBr₃ i) hexaboron silicide: B₆Si j) chlorine dioxide: ClO₂ k) hydrogen iodide: HI l) iodine pentafluoride:IF₅ m) dinitrogen trioxide:N₂O₃ n) ammonia: NH₃ o) phosphorus triiodide: PI³

What is an ionic compound

FORM BY JOINING METAL CATIONS AND NONMETAL ANIONS a) compounds that contain ionic bonds b) they are electrically neutral c) when the cation give electrons to the anion, the charges cancel out 1. MADE OF CATIONS AND ANIONS 2. METALS AND NONMETALS 3. The electrons lost by the cations are gained by the anion a) involved both metal and nonmetals 4. The cation and anions surround each other a) this shows that electrons that are lost by cations are gained by anions b) this is how they are bound c) cations and anions are formed when ionic compounds form 5. THE SMALLEST PIECE IS CALLED A FORMULA UNIT 6. Usually solid crystal 7. Melt at high temperatures

What are polyatomic ions and name the important ones with their formulas?

GROUPS OF ATOMS THAT STAY TOGETHER AND HAVE A CHARGE 1. Acetate: C₂H₃O₂¹₋ 2. Nitrate: NO₃¹⁻ 3. Hydroxide: OH⁻¹ 4. Cyanide Cn⁻¹ 5. permangonate: MnO₄¹⁻ 6. Sulfate: SO₄⁻² 7. Sulfite: SO₃⁻² 8. Chromate: CrO₄⁻² 9. Dichromate: Cr₂O₇⁻² 10. Phosphate: PO₄⁻³ 11. Phosphite: PO₃⁻³ 12. Ammonium: NH₄¹⁺ 13. nitrite:NO₂₋¹ 14. Hydrogen carbonate: HCO₃⁻¹ 15. Hypochlorite: CIO⁻¹ 16. Chlorite: CIO₂⁻¹ 17. Clorate: CIO₃⁻¹ 18. Perchlorate: CIO₄⁻¹ 19. bromate: BrO₃⁻¹ 20. Iodate: IO₃⁻¹ 21. Periodate: IO₄⁻¹ 22. Dihydrogen phsophate: H₂PO₄⁻¹ 23. Carbonate: CO₃⁻² 24. Thiosulfate: S₂O₃⁻² 25. Peroxide: O₂⁻² 26. hydrogen phosophate: HPO₄⁻² 27. arsenate: AsO₄⁻³

What are polyatomic ions

IONS MADE UP OF MORE THAN ONE ATOM 1. a polyatomic ion acts as an individual ion in a compound and its charge applies to the entire group of atoms 2. thus, the formula for a polyatomic compound follows the same rules used for a binary compound 3. because a polyatomic ion exists as a unit, never change subscripts of the atoms within the ion a) if more than one polyatomic ion is needed, place parentheses around the ion and write the appropriate subscript outside the parentheses

How do you draw the dot diagram for a covalent bond? How do you draw it for a polyatomic ion?

LEWIS STRUCTURE: represents the arrangement of electrons in a molecule a) in a line or a pair of vertical dots between the symbols of elements represents a single covalent bond in a Lewis structure 1. Example: CO₂ a) carbon is central atom (it is the more metallic so it goes in the center) b) the atom with the fewest valence electrons goes in the middle c) carbon has 4 valence electrons d) oxygen has 6 valence electrons e) there only solution is to share more electrons f) this requires a double bond g) each atom can now count all of the electrons in the bond h) the correct lewis diagram is O= C=O i) lines show the bonds and the ANGLE OF THE BOND IS IMPORTANT-CO₂ always has bonds straight like above 2. hydrogen is never on the inside because it only needs one more 3. Lines = show the type of bonds 4. Although the units act as anion, the atoms within a polyatomic ion are covalently bonded a) the procedure for drawing Lewis structures for polyatomic ions is similar to drawing them for covalent compounds b) the main difference is in finding the total number of electrons available for bonding c) compared to the number of valence electrons present in the atoms that make up the ion, more electrons are present if the ion is negatively charged and fewer are present if the ion is positive d) to find the total number of electrons available or bonding, first find the number available in the atoms present in the ion e) then subtract the ion charge if the ion is positive and add the ion charge if the ion is negative

What is Resonance

RESONANCE IS WHEN MORE THAN ONE VALID DOT DIAGRAM IS POSSIBLE a) occurs when more than one valid lewis structure can be written for a particular molecule due to position of double bond b) happens when there are double bonds in which you can move the position of the bonds (only move position of the double bond) c) the two or more correct lewis structures that represent a single molecule or ion are referred to as resonance structures 1. THERE IS NO CORRECT ANSWER FOR A RESONANCE BECAUSE bonds are constantly moving and flipping back and forth between 2 extremes a) not locked in place and constantly moving 2. it is actually a hybrid of the option structures. 3. to show it, draw all varieties possible and join them with a bold headed arrow (↔) 4. THE ACTUAL STRUCTURE IS AN AVERAGE OR HYBRID OF THESE STRUCTURES 5. EXAMPLE: O₃ (ozone) a) Can be O=O-O ↔ O-O=O b) notice the different location of the bond 6. Polyatomic ions: there id a difference in positions of the double bonds a) O=C-O. b) O-C-O | ‖ O O c) this is an example of a carbonate ion d) this is going to be a -2 charge because when the carbonate ion bonds with metal it picks up 2 electrons and is -2 7. ONLY DIFFER IN THE POSITION OF THE ELECTRON PAIRS, NEVER THE ATOM POSITIONS a) the location of the lone pairs and boding pairs differs in resonance structures

What is hydrogen bonding?

THE ATTRACTIVE FORCE CAUSED BY HYDROGEN BONDING TO NITROGEN, OXYGEN, FLUORINE, OR CHLORINE a) only these because they are the most electronegative elements on the periodic table 1. N, O, F, Cl are very electronegative so this is a very strong dipole 2. the hydrogen partially shared with the lone pair in the molecule next to it 3. THIS IS THE STRONGEST OF THE INTERMOLECULAR FORCES a) any of this elements bonded with hydrogen will have a hydrogen bond even it it is bonded with another element as well 4. forms between the hydrogen end of one dipole and a fluorine, oxygen, or nitrogen atom of another dipole 5. HYDROGEN BONDING IS WHEN A HYDROGEN ATOM IS: a) COVALENTLY BONDED TO A HIGHLY ELECTRONEGATIVE ATOM AND b) IS ALSO WEAKLY BONDED TO AN UNSHARED ELECTRON PAIR OF A NEARBY HIGHLY ELECTRONEGATIVE ATOM 6. The hydrogen is left very ELECTRON DEFICIENT thus it shares with something nearby 7. hydrogen is also the only element with NO SHIELDING for its nucleus when involved in a covalent bond a) no shielding cause it only has 1 valence electron so it gets pulled away from nucleus and nucleus is left unshielded and is pulled to anything nearby

How do you name ions?

THERE ARE TWO METHODS IF MORE THAN ONE CHARGE IS POSSIBLE: 1. STOCK SYSTEM: uses roman numerals in parenthesis to indicate the numerical value 2. CLASSICAL METHOD: uses root word with suffixes (-OUS, -IC) a) example: copper becomes cooperous, cooperic b) this does not give true value or charge 3. We will use the stock system a) it is mre precise and it tells you exactly what the charge is on the ion 4. Caton: if the charge is always the same (group A), just write the name of the metal 5. Transition metals can have more than one type of charge a) indicate the charge with roman numerals in parenthesis b) FeCl₃ is called iron (III) chloride 6. Anions are always the same charge a) no need for roman numerals b) change the element ending to -IDE (monoatomic nonmetals use this) c) change ending of the nonmetals d) always -ide when it is one metal by itself

What are the types of alloys and define them?

TYPES: 1. SUBSITITUTIONAL ALLOY: the atoms in the components are about the same size a) some of the atoms in the original metallic solid are replaced by other metals of similar atomic size b) example: sterling silver A) in sterling silver, copper atoms replace some of the silver atoms in the metallic crystal and the resulting solid has properties of both silver and copper 2. INTERSTITIAL ALLOY: the atomic sizes are quite different; smaller atoms fit into the spaces between larger a) formed when the small holes in a metallic crystal are filled with smaller atoms b) the best known is carbon steel A) the holes in the iron crystal are filled with carbon atoms and the physical properties of iron are changed B) iron is relatively soft and malleable C) the presence of carbon makes the solid harder, stronger, and less ductile than pure iron c) different sizes cause it to be stronger and more rigid

what are coordinate covalent bonds

WHEN ONE ATOM DONATES BOTH ELECTRONS IN A COVALENT BOND IT FORMS A COORDINATE COVALENT BOND a) happens when one there are a mix of double and single bonds b) when the other atom doesn't have enough electrons c) forms when one atoms donates both of the electrons to be shared with an atom or ion that needs two electrons to form a stable electron arrangement with lower potential energy d) atoms or ions with lone pairs often form coordinate covalent bonds with atoms or ions that need more electrons 1. the coordinate covalent bond is shown with an arrow (← or →) over the regular bond with the direction of the arrow pointed towards the element that is receiving the electrons a) ALWAYS KNOW A COORDINATE COVALENT BOND BY THAT SYMBOL 2. Most POLYATOMIC CATIONS AND ANIONS contain covalent and coordinate covalent bonds 3. EXAMPLE with Carbon monoxide a) carbon still needs 2 more electrons but oxygen has a full octet and has no more single electrons to share b) the oxygen has two unpaired electrons that it can donate to carbon to form another bond c) this will give carbon a full octet d) the electrons will shift and pair up to stabilize the atom e) the unpaired electrons are going to want to make a bond even though the oxygen atom is stable because of the electronegativity of the atom 4. EXAMPLE: NH₃ a) Nitrogen has 5 valence electrons and needs 3 more b) hydrogen has 1 valence electron and needs 1 more c) Nitrogen is electronegative so it will donate another valence electron to a nearby hydrogen atom (not a part of the original ammonia) which gives it a +1 charge d) donates both of them because the shell is full e) deals with electronegativity of N which creates a plus 1 charge because you are adding hydrogen (already at a full shell and adding one hydrogen which gives it a plus one charge) A) if electrons are available to bond, they will bond f) hydrogen needs to be in excess and take 1 electron

Write the formulas for the elements: a) potassium ion b) magnesium ion c) copper (II) ion d) chromium (VI) ion e) barium ion f) mercury (II) ion g) sulfide ion: h) iodide ion i) phosphide ion j) strontium ion

a) potassium ion: K⁺¹ b) magnesium ion: Mg⁺² c) copper (II) ion: Cu⁺² d) chromium (VI) ion: Cr⁺⁶ e) barium ion: Ba⁺² f) mercury (II) ion: Hg⁺² g) sulfide ion: S²⁻ h) iodide ion: I⁻¹ i) phosphide ion: P⁻³ j) strontium ion: Sr²⁺