CHEMTUTOR CHAP 4
Determine the charge on the copper ion in CuO. The oxide ion has a -2 charge because oxygen is in Group VIA. What charge must copper have to equal the negative charge? Cu=+1: 2(+1) + (−2) = 0
+2
METALS - LOSE electrons Since magnesium is in group IIA it loses two electrons to achieve a noble gas structure. If magnesium LOSES two electrons what will be the charge on the resulting magnesium ion?
+2
NON-METALS - GAIN electrons Since chlorine is in group VIIA it must gain one electron to achieve a noble gas structure. If chlorine GAINS one electron what will be the charge on the resulting chlorine ion?
-1
You can determine the charge on a metal ion in an ionic compound by using the charge on the non-metal (which does not vary). For example, determine the charge on the copper ion in CuO. What is the charge on the oxygen ion?
-2
When naming fixed-charge ionic compounds the following pattern is used: Metal name + stem name of non-metal + -ide The name of ionic compounds that contain only two elements will always end in _____.
-ide
The number of electrons in the HIGHEST energy shell for elements in the "A" GROUPS is always given by the GROUP NUMBER. How many electrons are in the HIGHEST energy shell for elements in group IIA?
2
Variable-charge metals can form more than one positive ion. For example, iron forms both Fe2+ ions and Fe3+ ions. The ability to form more than one positive ion must be taken into account when naming ionic compounds. How many positive ions can iron form?
2
NON-METALS - GAIN electrons Oxygen is in group VIA. Oxygen has six valence electrons and needs eight electrons to have a noble gas structure. How many electrons will oxygen gain? What will the charge be on an oxygen ion?
2, -2
The charge on a fixed-charge metal depends on its group. Group IA (all) +1 Group IB (Ag) +1 Group IIA (all) +2 Group IIB (Zn, Cd) +2 Group IIIA (Al, Ga) +3 Because Aluminum and Gallium are in Group IIIA they always form ions with a positive ____ charge.
3
Let's determine the formula for the ionic compound containing the following ions; Na+ and PO43- To make the positive and negative charges equal we need how many sodium ions _____? phosphate ions _____?
3, 1
Gilbert Lewis developed concepts about valence electrons and chemical bonding. Lewis recognized that the noble gases were unreactive and contained eight valence electrons (except helium) in their outer shell. How many electrons do the noble gases contain in their outer shell?
8
Give the number of protons and electrons in the ion: F- Protons ____ Electrons ____
9, 10
What is the formula for the compound formed between Be and P?
Be3P2
Determine the formula for the ionic compound containing; Ca2+ and NO3- Write the formula for this compound.
Ca(NO3)2
Write the formula for calcium nitride. Remember the charges must balance.
Ca3N2
Write the formula for the compound: copper (II) hydroxide
Cu(OH)2
Write the formula for copper (II) oxide.
CuO
Write the formula for the compound containing; Fe3+ and hydroxide
Fe(OH)3
Write the formula for the compound containing; K+ and CO32-
K2CO3
Give the formula for the ionic compound formed between bromine and magnesium.
MgBr2
Write the formula for magnesium chloride. Remember the charges must balance.
MgCl2
Write the formula for the compound: ammonium chloride
NH4Cl
Write the formula for the compound containing; ammonium and nitrate
NH4NO3
Give the formula for the ionic compound formed between sodium and fluorine.
NaF
The roman numeral (II) in nickel (II) chloride says that nickel has a +2 charge. What is the formula for nickel (II) chloride?
NiCl2
Write the formula for nickel (II) sulfide.
NiS
Metal Name + (Roman Numeral) + Nonmetal stem name + -ide When naming a variable-charge ionic compound the positive charge must be given by using a _______ ______.
Roman numeral
When naming compounds that contain variable-charge metals, the charge on the metal ion must be included in the name. The charge on the metal ion is indicated with a ROMAN NUMERAL, inside parentheses, placed after the metal name. Metal Name + (Roman Numeral) + Nonmetal stem name + -ide When naming compounds containing a variable-charge metal, the charge on the metal ion is given by a _____ _______.
Roman numeral
Which of the following compounds are ionic? a) NaCl b) NO2 c) CaO d) CO2
a, c
Name the following compound; AlBr3
aluminum bromide
The metal ion in Ca(OH)2 is a fixed-charge metal and the polyatomic ion is negative. What is the name of this compound?
calcium hydroxide
Elements are the building blocks of all matter. The attractive forces that cause atoms to stick together are called CHEMICAL BONDS. _________ _______ are the forces which hold atoms together in chemical compounds.
chemical bonds
Metal Name + (Roman Numeral) What is the name for Cr3+
chromium (III)
Metal Name + (Roman Numeral) + Nonmetal stem name + -ide What is the name for Cu2O?
copper (1) oxide
The charge on a variable-charge metal ion is given by a ROMAN NUMERAL. Metal Name + (Roman Numeral) The roman numeral is considered to be part of the name. Fe3+ iron (III) Fe2+ iron (II) Cu+ copper (I) What is the name for Cu2+ ion?
copper (II)
Determine the charge on the copper ion in Cu2O. For the charges to balance we use the equation: 2(copper charge) + oxygen charge = 0 2(copper charge) + (-2) = 0 2(copper charge) = +2 copper charge = +1 What is the name for the "copper ion" in Cu2O?
copper(1)
Metal Name + (Roman Numeral) + Nonmetal stem name + -ide What is the name for CuO? (copper has a +2 charge)
copper(II) oxide
The FIRST STEP in naming chemical compounds is to determine if the compound is ionic or covalent. IONIC COMPOUNDS: metals combined with non-metals COVALENT COMPOUNDS: non-metals combined with non-metals. Determining if a compound is ionic or covalent is the _____ ____ in naming chemical compounds.
first step
Since NaF is fixed-charge ionic compound we use the pattern; Metal name + stem name of non-metal + -ide What is the stem name of the non-metal in NaF?
fluor
There are two major types of chemcial bonds. These include IONIC BONDS and COVALENT BONDS. • An ionic compound is a compound in which ionic bonds are present. • A molecular compound is a compound in which atoms are joined through covalent bonds. What type of bond forms an ionic compound? ( ____ bonds)
ionic
There are two major types of chemical bonds. These include IONIC BONDS and COVALENT BONDS. • Ionic bonds result from the TRANSFER of electrons from one atom or group of atoms to another. • Covalent bonds result from the SHARING of electron PAIRS between atoms. The major types of chemical bonds are i______ and c______ bonds.
ionic, covalent
There are two broad classes of chemical compounds: • Ionic compounds • Molecular compounds The major types of chemical compounds are i______ and m_______ compounds.
ionic, molecular
Polyatomic ions are very stable and tend to act like a single non-metal atom. During chemical reactions, polyatomic ions stay together and do not break apart. However, they never occur alone but are always combined with other ions. Polyatomic ions are always combined with other _____.
ions
Name the following pair of ionic compounds; FeO and Fe2O3
iron (II) oxide, iron (III) oxide
Name the following compound; Mg3N2
magnesium nitride
Name the following compound: Mg3(PO4)2
magnesium phosphate
Name the following pair of ionic compounds; MnO and MnO2
manganese (II) oxide, manganese (IV) oxide
Naming compounds containing polyatomic ions is similar to naming other ionic compounds except for; 1. Positive polyatomic ion - its name is substituted for the metal name. 2. Negative polyatomic ion - its name is substituted for the stem name plus "ide" of the non-metal. Positive polyatomic ion names are used in place of the ______ name.
metal
When naming fixed-charge ionic compounds that contain only two elements the following general pattern is used: Metal name + stem name of non-metal + -ide What name comes first in naming an ionic compound? (metal, non-metal)
metal
Consider the following particles of sulfur. S S2- Sulfur (S) has an atomic number 16. Therefore, a sulfur atom has 16 electrons and 16 protons. The ion S2- has gained two extra electrons, so it has a total of (16+2) or 18 electrons. Since there are two more electrons than protons it has a -2 charge. Atoms that gain electrons will have a (positive, negative) charge?
negative
Name the following compound; (NH4)2SO4 1. Is the positive ion a variable-charge metal? (yes, no) 2. Name of positive ion _______? 3. Name of negative ion ________? 4. Name of compound __________ ________?
no, ammonium, sulfate, ammonium sulfate
Name the following compound; K3P
potassium phosphide
Naming ionic compounds containing polyatomic ions is similarto naming binary ionic compounds. The rule for naming binary ionic compounds is to give the name of the metal (including a Roman numeral if needed) followed by the non-metal stem name. Naming compounds containing polyatomic ions is ______ to naming other ionic compounds.
similar
Since NaF is a fixed-charge ionic compound we use the pattern; Metal name + stem name of non-metal + -ide What is the name of the metal in NaF?
sodium
Variable-charged metal ions do not always lose the same number of electrons. Therefore, variable-charge metals can have different positive charges. For example, iron sometimes forms Fe2+and other times Fe3+ions. Iron can form ions with more than one type of positive ion. (true, false)
true
Consider the following compound; Ca(OH)2 Is the metal ion a fixed-charge metal? (yes, no)
yes
There are two special customs used for compounds containing polyatomic ions. (1) When more than one polyatomic ion is present it is placed inside parentheses with a subscript outside the parentheses to indicate the number of polyatomic ions present. (2) To preserve the identity of polyatomic ions, element symbols may be used more than once in the formula. Can a chemical symbol be used more than once in a chemical formula? (yes, no)
yes
Name the following compound; Fe2(CO3)3 1. Is the positive ion a variable-charge metal? (yes, no) 2. Name of positive ion _______? 3. Name of negative ion ________? 4. Name of compound _______ ___ ________?
yes, iron (III), carbonate, iron (III) carbonate
Beryllium, magnesium, and calcium are in group IIA. Look at Table 3.1. How many electrons are in the HIGHEST energy shell of these elements?
2
What is the formula for the compound formed between Al and P?
AlP (lowercase L)
Hydrogen, lithium, sodium, and potassium are in group IA. Look at Table 3.1. How many electrons are in the HIGHEST energy shell (outer-most shell) of hydrogen, lithium, sodium, and potassium?
1
NON-METALS - GAIN electrons Because of the octet rule, NON-METALS gain electrons to obtain a noble gas structure. Chlorine is in group VIIA. Look at Table 3.1, chlorine has seven valence electrons. The electron configuration is 1s22s22p63s23p5, or 2-8-7, indicating the total # of electrons in each of the three energy shells. How many valence electrons must chlorine gain to achieve a noble gas structure?
1
METALS - LOSE electrons Sodium is in group IA. How many electrons will sodium lose? What will the charge be on a sodium ion?
1, +1
NaCl (salt) Application of the octet rule shows how sodium and chlorine form an ionic compound. Sodium is a Group IA metal with one valence electron. Chlorine is a Group VIIA non-metal with seven valence electrons. Sodium is a metal and will lose how many electrons? ____ Chlorine is a non-metal and will gain how many electrons? ____
1, 1
Indicate the number of electrons lost when the following metallic elements form ions. Na Ca Sr Al
1, 2, 2, 3
Consider the reaction between sodium and oxygen. Oxygen needs two electrons since it is in Group VIA. Sodium loses only one electron since it is in Group IA. Therefore, one oxygen atom needs two sodium atoms to meet its need for two additional electrons. The electron transfer between sodium and oxygen is shown above. How many sodium atoms must react with one oxygen atom?
2
Electron dot symbols along with the octet rule are used to predict formulas for ionic compounds. Consider the reaction of calcium with oxygen. According to the octet rule calcium will give up two electrons to form Ca2+. The octet rule says oxygen will gain two electrons to form O2-. The reaction of a calcium ion with an oxide ion is shown as follows: Ca2+ + O2-→ CaO How many electrons are transferred when calcium and oxygen react to form an ionic compound?
2
METALS - LOSE electrons. Because of the octet rule, METALS lose their valence electrons to obtain a noble gas structure. Magnesium is in group IIA. Look at Table 3.1, magnesium has two valence electrons. The electron configuration for magnesium is 1s22s22p63s2 . Another way this is sometimes shown is Mg: 2-8-2, indicating the total number of electrons in each of the three energy shells. How many electrons must magnesium lose to have a noble gas structure?
2
The electron dot symbols above show how electrons are transferred when calcium and oxygen react. The calcium (+2) ion has lost how many electrons? The oxygen (-2) ion has gained how many electrons?
2, 2
Predict the number of electrons lost or gained and the resulting ionic charge when the following atom forms an ion. Se (Number, lost or gained, charge)
2, gained, -2
Compounds that contain polyatomic ions are ionic. Their formulas are determined and written the same way as other ionic compounds. The only difference is that when more than one polyatomic ion is present in a compound it is put in parentheses. For example, aluminum sulfate is written; Al2(SO4)3 How many sulfate ions are in aluminum sulfate?
3
The charge on an ion is directly related to how many electrons it has lost or gained. An atom that loses two electrons will have a +2 charge. An atom that gains two electrons will have a -2 charge. An ion that has a -3 charge has gained how many electrons?
3
Give the number of protons and electrons in the ion: Li+ Protons ___ Electrons ___
3, 2
The reaction of magnesium with nitrogen also forms an ionic compound. Magnesium is in Group IIA and loses two electrons to form Mg2+. Nitrogen is a non-metal in Group VA and gains three electrons to form N3-. Since magnesium nitride is neutral the positives and negatives must be the same. The electron transfer is shown above. How many magnesium atoms are needed? How many nitrogen atoms are needed?
3, 2
Electron dot symbols for GROUP IA are shown above. Since all elements in the same group have the same number of valence electrons, they have the same electron dot symbol. All elements from GROUP IVA will have how many dots?
4
Look at phosphorus (P) in Table 3.1. Phosphorus has a total of 15 electrons; 2 in the first shell 8 in the second shell 5 in the third shell. How many valence electrons does phosphorus have?
5
When magnesium reacts with nitrogen they form a neutral ionic compound. Therefore, three Mg2+ ions (+6) are needed to balance two N3- ions (-6). Six electrons have been transfered when three magnesium atoms react with two nitrogen atoms. When magnesium reacts with nitrogen, how many total electrons are transferred from the magnesium atoms to the nitrogen atoms?
6
Ionic solids are made up of large numbers of alternating positive and negative ions that form a crystal lattice. A model of sodium ions (red) and chloride ions (blue) is shown above. Positive ions (sodium) tend to be near negative ions (chloride). Likewise, negative ions tend to be near positive ions. How many sodium ions are around a chloride ion? How many chloride ions are around a sodium ion?
6, 6
Neon and argon are in group VIIIA. How many electrons are in the HIGHEST energy shell of these elements?
8
Ca2+ + O2-→ CaO Calcium and oxygen react in a ratio of 1:1 since calcium loses two electrons and oxygen gains two electrons. What is the correct formula for the ionic compound formed between calcium and oxygen?
CaO
Give the formula for the ionic compound formed between potassium and sulfur.
K2S
3Mg2+ + 2N3- → Mg3N2 Note how three magnesium ions lose six electrons and two nitrogen ions gain six electrons. What is the correct formula for the compound formed between magnesium and nitrogen?
Mg3N2
2Na+ + O2-→ Na2O Note how the need of oxygen for two electrons requires two sodium atoms for every oxygen atom. What is the correct formula for the compound formed between sodium and oxygen? (NaO, Na2O, 2NaO, NaO2)
Na2O
What polyatomic ion is in the following compound? NH4Cl
ammonium
Consider the electron dot symbols shown above. Which electron dot symbol is correct for Se?
c (6 dots)
The atoms of elements are neutral because the number of protons (positive charges) equals the number of electrons (negative charges). Atoms become CHARGED when the number of protons and electrons are not equal. The loss or gain of electrons destroys the proton-electron balance and leaves the atom with a ________.
charge
Covalent bonds result from the SHARING of electron PAIRS between atoms. The SHARING of electron pairs between atoms makes what type of chemical bond? (ionic, covalent)
covalent
There are two major types of chemcial bonds. These include IONIC BONDS and COVALENT BONDS.• An ionic compound is a compound in which ionic bonds are present.• A molecular compound is a compound in which atoms are joined through covalent bonds. What type of bond forms a molecular compound? ( ____ bonds)
covalent
Certain groups of covalently bonded atoms tend to stay together to form charged molecular ions. These groups of atoms tend to behave like a single non-metal atom. A group of covalently bonded atoms that have acquired a charge through electron transfer is a POLYATOMIC ION. The atoms in a polyatomic ion are (ionically, covalently) bonded.
covalently
The elements in a compound are held together by chemical bonds. Chemical bonds between atoms are formed in very definite ways. The atoms combine according to rules that are determined by the ELECTRON STRUCTURE of the atoms. The __________ __________ determines how atoms combine.
electron structure
Sodium chloride is a neutral substance (doesn't have a charge). There must be one sodium (+1) ion for every chloride (-1) ion to be neutral. To show this composition the formula for sodium chloride is written; NaCl To be a neutral substance the positive charges and negative charges must be (different, equal).
equal
Table 4.2 gives the names and formulas of several common polyatomic ions. Note that almost all polyatomic ions contain oxygen. Many of the polyatomic ion names should be familiar because they are found in many consumer products; for example, baking powder and soda (bicarbonates), fertilizers (nitrates, phosphates, sulfates), and building materials (carbonates, sulfates). What materials contain phosphates?
fertilizers
IONIC bonds result from the TRANSFER of electrons from one atom or group of atoms to another. Because ionic bonding involves the transfer of electrons, one atom GAINS electrons and the other atom LOSES electrons. An ionic bond forms when one atom g_____ electrons and the other atom l_____ electrons.
gains, loses
Na+ + Cl- → NaCl (salt) The electron dot notations for sodium, chlorine, and sodium chloride are shown above. The reaction of sodium with chlorine is basically a transfer of an electron from sodium to chlorine. Sodium (gives, receives) an electron (to, from) chlorine when they react to form an ionic compound.
gives, to
The electrons in the highest energy shell are the most important electrons in the atom. These are the electrons which determine the chemical properties of the element. The chemical properties of an element are determined by the electrons in the (lowest, highest) energy shell.
highest
Ionic bonding or electron transfer gets its name from the word ION. • An ION is a charged atom. Ions or charged atoms are formed when atoms gain or lose electrons. An ____ is an atom that is charged because it has lost or gained electrons.
ion
Ionic bonds result from the TRANSFER of electrons from one atom or group of atoms to another. The TRANSFER of electrons between atoms or groups of atoms makes what type of chemical bond? (ionic, covalent)
ionic
Polyatomic ions are very stable species. However, they are not molecules; they never occur alone as molecules do. Polyatomic ions combine with other ions to form ionic compounds. These ionic compounds contain both positive and negative ions. Polyatomic ions always combine with other ions to form ______ compounds.
ionic
IONIC bonds result from the TRANSFER of electrons from one atom or group of atoms to another. Loss and gain of electrons always occur simultaneously. The electrons lost by one atom are the same electrons gained by the other atom. Therefore, the formation of positive and negative ions always occur together. For an element to gain electrons a different element must ______ electrons.
lose
An ion with a charge of +3 has (gained, lost) three electrons.
lost
• POSITIVE ION - results from the loss of electrons. • NEGATIVE ION - results from the gain of electrons. Positive ions have (gained, lost) electrons. Negative ions have (gained, lost) electrons.
lost, gained
There is no easy way to learn the polyatomic ions. You must memorize their names, formulas, and charges to be successful in chemistry. Not being able to recognize polyatomic ions in compounds will be a major problem. The only way to learn the polyatomic ions is to _________ them.
memorize
As a general rule, the representative elements behave as follows to obtain a noble gas electron structure (eight electrons in their outer shell). METALS - LOSE electrons. NON-METALS - GAIN electrons. If an element LOSES electrons it is a (metal, non-metal). If an element GAINS electrons it is a (metal, non-metal).
metal, non-metal
When an atom gains electrons there will be more electrons than protons. Since electrons are negatively charged, atoms that gain electrons will have a NEGATIVE (-) charge. When an atom gains electrons it will have a (negative, positive) charge.
negative
A key concept in modern chemistry developed by Lewis is known as the OCTET RULE: • When atoms react, they tend to LOSE, GAIN, or SHARE valence electrons to achieve the same electron arrangement as their nearest noble gas (eight electrons in the outer most shell). The tendency for atoms to lose, gain, or share valence electrons so that they can have a noble gas electron structure is known as the ______ ______.
octet rule
The OCTET RULE correctly explains how atoms combine to form many different molecules. For example, it explains why two hydrogens are bonded to one oxygen to form water. It explains why common table salt has the formula NaCl (one sodium combined with one chlorine). The way atoms combine to form compounds is explained by the _____ _____.
octet rule
The electrons in the highest energy shell are the most important electrons in the atom. Since these electrons are the farthest out, they are the electrons that interact when atoms come together to form compounds. When atoms come together, only the electrons in the (innermost, outermost) shell interact.
outermost
Only the electrons in the outermost shell interact when atoms come together. These outermost electrons are called VALENCE electrons. The electrons which interact when atoms come together are in the __________ shell and are known as __________ electrons.
outermost, valence
Consider the following particles of sodium. Na Na+ Sodium (Na) has an atomic number 11. Therefore, a sodium atom has 11 electrons and 11 protons. The ion Na+ has lost an electron, and contains (11-1) or 10 electrons. Since there is one more proton than electrons it has a +1 charge. Atoms that lose electrons will have a (positive, negative) charge?
positive
When an atom loses electrons it will have more protons than electrons. Since protons are positively charged, atoms that lose electrons will have a POSITIVE (+) charge. When an atom loses electrons it will have a (negative, positive) charge.
positive
NaCl (salt) When sodium and chlorine react to form sodium chloride, sodium loses an electron and becomes a positive ion and chlorine gains an electron and becomes a negative ion. In the ionic compound NaCl, sodium has a (positive, negative) charge and chlorine has a (positive, negative) charge.
positive, negative
Ionic compounds are neutral so positive charges must equal negative charges. The number of metal and non-metal atoms in an ionic compound is given by the RATIO of positive and negative charges that make them equal. The numbers in an ionic formula are given by the _____ of positive to negative charges that make the compound neutral.
ratio
We can see from the figure that discrete molecules DON'T exist in an ionic solid. There is no unique molecule in ionic structures; no ion is attracted exclusively to another ion. Therefore, the formulas for ionic materials represent the RATIO of metal ions to non-metal ions in the crystal lattice. Ionic formulas give the _______ of metal ions to non-metal ions.
ratio
There are exceptions to the octet rule, but it is still very useful because it explains the composition of so many compounds. The octet rule is particularly useful in explaining how the REPRESENTATIVE ELEMENTS (A-groups) combine to form compounds and molecules. The compounds formed by (representative, transition) elements can be explained by the octet rule.
representative
A crystal lattice is made up of huge numbers of ions grouped together in a regular, repeating pattern. Because bonding in the crystal lattice is between many ions, ionic compounds are very stable. For example, ionic solids tend to have high melting points. Ionic bonding makes compounds (stable, unstable).
stable
The noble gases are in group VIIIA. All the noble gases except helium contain eight electrons in their outer shell. Because all the noble gases are non-reactive, the valence electron structure of the noble gases is considered to be the most stable of all valence electron configurations. The electron structure of the noble gases is considered to be (reactive, stable).
stable
The octet rule says that atoms in a compound will LOSE, GAIN, or SHARE valence electrons to achieve a (reactive, stable) electron structure like a noble gas.
stable
What is the name of the polyatomic ion in the following compound? ZnSO4
sulfate
Although polyatomic ions are covalently bonded, they form ionic bonds with other ions. Thus, compounds containing polyatomic ions are ionic. Polyatomic ions form ionic compounds. (true, false)
true
Sodium chloride or table salt is always a good place to start when talking about ionic bonds and ionic compounds. Let's review what we know about sodium chloride. It is a white crystalline solid. It is composed of sodium and chlorine, a metal and a non-metal. Sodium chloride is an ionic solid made up of a metal and a non-metal. (true, false)
true
When the outermost energy level of an atom contains eight electrons the atom is non-reactive (stable) because it has a noble gas structure. Atoms of an element try to lose, gain, or share electrons to achieve eight electrons in their outer shell to become non-reactive. When an atom has eight electrons in its outer shell it is non-reactive. (true, false)
true
Only the valence electrons are involved in chemical bonding. For the representative elements (group A elements) the valence electrons are found in the outermost shell. The electrons involved in chemical bonds are the __________ electrons.
valence
The elements in a compound are held together by chemical bonds. Valence electrons determine how these bonds form between the atoms. The valence electrons are the glue in the chemical bonds that hold atoms together in a compound. Chemical bonds between atoms are determined by their _________ electrons.
valence
There is an easy way to picture the number of valence electrons for the elements in the "A" Groups. Electron dot symbols show how many valence electrons an element has. An electron dot symbol consists of the element's chemical symbol and one dot for each valence electron placed around the symbol. The electron dot symbol is a way to picture an atom's _______ electrons.
valence
Ionic compounds are made up of nearly endless arrays of ions. A chemical formula shows the ratio of ions present in the compound. For example, sodium chloride has the formula NaCl because it has one Na+ ion for each Cl- ion. Is the ratio of calcium to chlorine in CaCl2 1:2. (yes, no)
yes
It is not always necessary to write electron dot structures to determine the formula for an ionic compound. Ionic formulas can be determined using the charges associated with the ions. The positive and negative charges must be equal because the electron transfer must balance. The number of electrons lost must always equal the number of electrons gained when an ionic compound is formed. (yes, no)
yes
Determine the formula for the ionic compound containing; Na+ and PO43- The formula for this compound needs three sodiums and one phosphate. Write the formula for the ionic compound.
Na3PO4
Write the formula for the compound: sodium bicarbonate
NaHCO3
What is the charge on nickel in the compound nickel (II) chloride?
+2
The CHLORIDES of Fe2+ and Fe3+ are FeCl2 and FeCl3, respectively. These ionic compounds are named; FeCl2 iron (II) chloride. FeCl3 iron (III) chloride. What is the charge on iron (II)? What is the charge on iron (III)?
+2, +3
Atoms form ions because they tend to gain or loss electrons to obtain the nearest noble gas configuration. The charge on an ion is given by a superscript placed next to the chemical symbol. Examples include: Positive ions: Na+ Be2+ Al3+ Negative ions: Cl- O2- N3- Note: For multiple charged ions, the number comes before the sign. For example, an aluminum ion has a +3 charge and is written as Al3+. What is the charge on a beryllium (Be) ion? What is the charge on a nitrogen (N) ion?
+2, -3
Formulas for ionic compounds containing polyatomic ions are determined in the same way as they are for other ionic compounds. The total positive and negative charge must add to zero. In a compound containing polyatomic ions the total charge must equal ______.
0
Ionic compounds contain positively charged metal ions and negatively charged nonmetal ions. Ionic compounds can be divided into two categories based on the identity of the metal ion that is present. 1. Fixed-charged ionic compounds contain a metal that only forms one type of positive ion. 2. Variable-charged ionic compounds contain a metal that forms more than one type of positvie ion. There are how many types of ionic compounds?
2
Predict the number of electrons lost or gained and the resulting ionic charge when the following atom forms an ion. Be (Number, lost or gained, charge)
2, lost, +2
Indicate the number of electrons gained when the following non-metallic elements form ions. N Cl S
3, 1, 2
Electron dot symbols for the second row elements are shown above. Dots for the valence electrons are placed one at a time around the symbol. It is not critical where the dots are placed. However, dots are not paired up until all four sides are used. How many dots are around boron? How many valence electrons does boron have?
3, 3
Sodium is in Group IA and loses one electron to form Na+. Phosphorus is in Group VA and gains three electrons to form P3-. For the positive charge to equal the negative charge, three sodium ions must react with one phosphorus ion. This gives the formula: Na3P. The number of positive charges equals? The number of negative charges equals?
3, 3
Positive ions are surrounded by negative ions, and negative ions are surrounded by positive ions. There is NO single chloride bonded to a specific sodium ion. Any given ion is bonded to all the other ions of opposite charge that surround it. How many chloride ions are bonded to one sodium ion? How many sodium ions are bonded to one chloride ion?
6, 6
Look at sulfur (S) in the periodic table. Give the following information: Group Number _____ Outer shell electrons _____ Valence electrons _____ Total electrons _____
VIA, 6, 6, 16
Since the group number for the "A" groups is equal to the number of electrons in the outermost shell, it is also equal to the number of valence electrons. What is fluorine's (F) group number? How many electrons are in the outermost shell of fluorine? How many valence electrons does fluorine have?
VIIA, 7, 7
There are 92 naturally occurring elements which combine together to form millions of chemical compounds. The naturally occurring elements are the BUILDING BLOCKS of all matter. The atoms of elements combine with one another to form new substances or compounds. We have learned that compounds are the chemical combination of TWO or more elements. Elements are the ________ _______ of all matter.
building blocks
The identity of an element is determined by the number of protons. However, the chemical properties of an element result from the arrangement of electrons around the nucleus. The arrangement of electrons in an atom determines its (identity, chemical properties)
chemical properties
When naming fixed-charge ionic compounds the following pattern is used: Metal name + stem name of non-metal + -ide Table 4.3 gives the stem names of the common non-metals. The stem name is always the first few letters of the non-metal's name. What is the stem name for chlorine?
chlor
Electron dot symbols for the second row elements are shown above. Notice the placement of dots around the chemical symbol. If an element has four valence electrons it has four dots. There is one ____ for each _______ electron in an electron dot symbol.
dot, valence
Only a limited number of fixed-charged metals exist. If you learn the fixed-charge metals, all other metals will be variable-charge metals. The fixed-charged metals are Group IA and IIA metals plus Al, Ga, Zn, Cd, and Ag. All metals in Group IA and IIA are ______-______ metals.
fixed, charged
We have learned that metals lose electrons when forming ions. Fixed-charged metals always lose the same number of electrons when forming positive ions. Therefore, fixed-charge metals ions will always have the same charge. A metal ion which always has the same charge is a ______-______ metal ion.
fixed, charged
Let's name the compound: NaF The first step is to determine if the compound is ionic or covalent. Remember ionic compounds are metals plus non-metals. NaF is (ionic, covalent).
ionic
Na+ + Cl- The strong electrostatic attraction between positive sodium and negative chloride ions makes the IONIC BOND. The attraction between positive and negative charges makes an _______ bond.
ionic
Consider the following compound; Ca(OH)2 The polyatomic ion is (positive, negative). What is the name of the polyatomic ion?
negative, hydroxide
The vast majority of metals form ions with a variable-charge. The charge on the variable-charge metals cannot be easily related to periodic table position. Therefore, the charge on a variable-charge metal ion must be given. Can the charge on a variable-charge metal ion be determined from the periodic table? (yes, no)
no
Since NaF is a fixed-charge ionic compound we use the pattern; Metal name + stem name of non-metal + -ide What is the name of NaF?
sodium fluoride
So far we have only looked at fixed-charge ionic compounds. Variable-charge metals are less predictable than the fixed-charge metals. Variable-charge metals can lose different numbers of electrons to form more than one positive ion. Can variable-charge metals form more than one positive ion? (yes, no)
yes
Name the following compound; CuCl 1. Is the compound ionic? (yes, no) 2. Is the metal a variable-charge metal? (yes, no) 3. Charge on the metal ion ____? 4. Metal name ________? 5. Non-metal stem ______? 6. Compound name ________ ___ ________?
yes, yes, +1, copper (I), chlor, copper (I) chloride
Name the following compound; AgCl Is the compound ionic? (yes, no) Is the metal a fixed-charge metal? (yes, no) Charge on the metal ion ____? Metal name ________? Non-metal stem ______? Compound name ________ ________?
yes, yes, +1, silver, chlor, silver chloride
Name the following compound; TiCl4 1. Is the compound ionic? (yes, no) 2. Is the metal a variable-charge metal? (yes, no) 3. Charge on the metal ion ____? 4. Metal name ________? 5. Non-metal stem ______? 6. Compound name ________ ___ ________?
yes, yes, +4, titanium (IV), chlor, titanium (IV) chloride
Name the following compound; CaO 1. Is the compound ionic? (yes, no) 2. Is the metal a fixed-charge metal? (yes, no) 2. Metal name ________? 3. Non-metal stem ______? 4. Compound name ________ ________?
yes, yes, calcium, ox, calcium oxide
