ch 9
What is the term used to describe the amount of energy required and/or released when a compound is formed from its elements?
Heat of formation
Match each metal ion to the correct Roman numeral that would be used when naming an ionic compound when appropriate.
III- Fe3+ II- Cr2+ I- Cu+
Which of the following statements about electron transfer in ionic bond formation is true?
The number of electrons lost must equal the number of electrons gained by atoms when an ionic bond is formed.
Potassium perchlorate
The perchlorate ion is ClO4-.
Two atoms may bond by sharing electrons. This type of bond is called a(n) _____ bond.
covalent
A(n) ______ bond results if the absolute difference in electronegativity between the two bonded atoms is 0.5 or less. If the difference in electronegativity between the two atoms is greater than 1.7, a(n) ______ bond results.
covalent; ionic
nonmetals
form ions with a charge equal to their family number minus 8
Oxygen sometimes occurs as molecules of three oxygen atoms bound together. These triatomic oxygen molecules (tri- means "three") are called
ozone
A covalent bond in which the electrons are shared unequally is called a(n) _____ covalent bond. The atoms of the bond have partial negative and positive _____ due to an unequal electron distribution.
polar; poles
Match the appropriate name to its salt, paying particular attention to the suffix used.
NaNO3- Sodium nitrate NaNO2- Sodium nitrite (ClO3)--Chlorate (ClO2)-- Chlorite
Which of the following options is the correct systematic name for Na2CO3?
Sodium carbonate
Which of the following is the correct name for the covalent compound SO2?
Sulfur dioxide
Which of the statements about the octet rule is true?
The octet rule states that atoms tend to try to achieve the same electron configuration as the closest noble gas.
Select all that apply Which of the following statements about the ions formed by transition elements are true? (Select all that apply.)
Transition elements produce positive ions. The ions formed by some transition elements are not easily predicted from the periodic table.
chemical equation
a way of describing what happens in a chemical reaction
_____ bonds occur when an atom of a metal reacts with an atom of a nonmetal.
ionic
Lithium iodide (LiI) is an ionic compound. The metal lithium ______ an electron to form the ion Li+, and the nonmetal iodine ______ an electron to form the ion I-. The ions are held together by ______ in a crystal lattice.
loses; gains; a strong electrostatic attraction
When naming a covalent compound, the number of atoms of each element is indicated by a Greek numerical _____. The first element in the name is numbered only when more than _____ atom(s) of that element is(are) present.
prefix; 1
The octet rule
states that after the element helium, atoms attempt to acquire an outer orbital with eight electrons through chemical reactions.
Select all that apply Which of the following statements correctly describe the formation of ionic bonds? (Select all that apply.)
An ionic bond results from the combination of positive and negative ions. An ionic bond results from the transfer of electrons. An ionic bond typically forms when a metal reacts with a nonmetal.
The relative ability of a bonded atom to attract shared electron pairs is called its _____.
electronegativity
What is the correct name for KClO3?
Potassium chlorate
chemical reaction
a change in matter where different chemical substances are created by breaking and/or forming chemical bonds.
The new chemical substances are on the right side of the word equation and are called
products
atom
the smallest unit of an element that can exist alone or in combination with other elements.
Atoms that achieve an octet by sharing electrons form covalent bonds. ionic bonds. metallic bonds. hydrogen bonds.
Answer a
What kind of bond has unequal sharing of bonding electrons? Polar covalent Covalent Ionic Polar ionic
Answer a
"Atoms attempt to acquire an outer orbital with eight electrons" is a statement of the Heisenberg certainty theory. atomic theory. octet rule. chemical energy balancing rule.
Answer c
The family or group number of the representative elements represents the total number of electrons. total number of protons. total number of valence electrons. atomic number.
Answer c
What is the chemical symbol for a magnesium ion? Mg+ Mg− Mg2+ Mg2−
Answer c
Which of the following is an example of a monatomic molecule? O2 N2 Ar O3
Answer c
Select all that apply Which of the following statements are true about the difference in electronegativity of two bonded atoms? (Select all that apply.)
The difference in electronegativity between two bonded atoms can be used to predict whether a bond is ionic or covalent. When the difference in electronegativity between two bonded atoms is taken, the absolute value of this number is used for evaluation.
A covalent compound is a compound that contains only covalent
bonds
Elements combine to form compounds by making chemical _____, which are formed by gaining, losing, or sharing _____.
bonds; electrons
Both hydrogen and oxygen occur naturally as
diatomic molecules
Chemical formulas describe what elements are present in a compound and in what proportions. The proportions are indicated by a _____ on the lower _____ of the element's symbol.
subscript; right
Select all that apply Which of the following options correctly name the covalent compound from the given chemical formula? (Select all that apply.)
OCl2: oxygen dichloride XeF4: xenon tetrafluoride
Select all that apply Which of the following options correctly describe the rules used to name an ionic compound containing a polyatomic ion? (Select all that apply.)
The metal ion is named first by using the parent name of the metal. The names and formulas of polyatomic ions are not found on the periodic table. They must be memorized or provided.
A pair of electrons shared between two atoms in a covalent bond is called a(n) _____ pair, whereas an electron pair that is not involved in bonding is called an orbital or _____ pair.
bonding; lone
The substances that are changed are on the left side of the word equation and are called
reactants
Chemical Energy
a form of energy involved in chemical reactions associated with changes in internal potential energy; a kind of potential energy that is stored and later released during a chemical reaction
alkali and alkaline earth metals
form ions of the same charge as the family number
Select all that apply Which of the following statements correctly describe a covalent bond? (Select all that apply.)
A stable covalent bond is formed through nucleus-electron attractions. As two atoms form a covalent bond, the stability of the system increases. If the two atoms in a covalent bond approach too closely, they will repel each other.
Select all that apply Using the electronegativity values provided, select all bonds that are polar covalent bonds.
N-B S-O
In the modern naming system, Roman numerals are used to name ionic compounds containing a metal that can form _____ ion(s). The Roman numeral specifies the _____ on the metal.
multiple; charge
The family number of the representative element in the periodic table tells you the number of valence electrons and suggests what the atom must do to reach the stability suggested by the octet rule.
sometimes it's easier to give electrons away to achieve a stable outer orbital than to acquire 5, 6, or 7 additional electrons
The Greek prefix used to indicate four atoms of the same element in a covalent compound is _____-, whereas the prefix deca- is used to indicate _____ atoms of the same element.
tetra; 10
ssium hypochlorite
The hypochlorite ion is ClO-.
Which statement correctly describes inner electrons?
These electrons are in the most stable and often fully occupied orbitals.
When Sr ionizes, it forms an ion with the charge _____, and when K ionizes, it forms an ion with the charge _____.
2+; 1+ Reason: Sr is in group IIA, which means it will lose two electrons to achieve the same electron configuration as the closest noble gas. K is in group IA. meaning it will lose one electron to achieve the same electron configuration as the closest noble gas.
Solve for the chemical formula of dichlorine pentoxide, Cl _____ O _____. Enter your answer in the correct format.
2; 5
The covalently bonded species shown has _____ bonding pair(s) and _____ lone pair(s).
3; 1
he number of covalent bonds formed by nonmetals is equal to ______.
8 minus the family number
Select all that apply Which of the following statements correctly describe a polar covalent bond? (Select all that apply.)
A covalent bond between atoms whose electronegativities differ is polar. In a polar covalent bond, the bonding electrons spend more time near the more electronegative atom.
Select all that apply Which of the following statements correctly describe the general characteristics of a covalent bond? (Select all that apply.)
A covalent bond involves the sharing of electrons between two atoms. A covalent bond involves the attraction between the nucleus of each atom and the electrons of the other. A covalent bond completes the octet for each atom involved in the bond.
Which of the following statements correctly describes a covalent compound?
A covalent compound contains only covalent bonds.
Select all that apply What are the ways that a pair of bonding electrons can be depicted? (Select all that apply.)
A- single line B- 2 dots
Select all that apply Which of the following formulas for ionic compounds are correct? (Select all that apply.)
AlCl3 Na2S
The electrostatic attraction between positive and negative ions is called a (an) ionic bond. metallic bond. covalent bond. electrostatic bond.
Answer a
The smallest particle of a compound or a gaseous element that can exist and still retain the characteristic properties of that substance is a (an) molecule. element. atom. electron.
Answer a
What determines the chemical properties of an atom? Valence electrons Atomic weight Neutrons and protons Protons only
Answer a
The comparative ability of atoms of an element to attract bonding electrons is called electron attraction. electronegativity. bonding. electron transfer.
Answer b
The energy released during the formation of an ionic bond is ionic energy. heat of formation. activation energy. heat of creation.
Answer b
The smallest unit of an element that can exist alone or in combination with other elements is a (an) nucleus. atom. molecule. proton.
Answer b
The correct name for the compound CS2 is dicarbon disulfide. carbon disulfite. carbon disulfide. monocarbon trisulfide.
Answer c
Which of the following is not true of a compound? It is a pure substance. composed of combinations of atoms. held together by chemical bonds. a substance that cannot be broken down into simpler units.
Answer d
Select all that apply Which of the following ion combinations will result in an ionic compound that has a balanced number of positive and negative charges? (Select all that apply.)
Ba2+ and 2 Cl- 2 Li+ and S2- Na+ and Br-
Select all that apply In an electron dot structure, what can two dots represent? (Select all that apply.)
Bonding pair Lone pair
Select all that apply Which of the following statements about a chemical reaction are true? (Select all that apply.)
Chemical bonds are broken and/or made during a chemical reaction. A chemical reaction is the process used to describe a chemical change.
What is an easy way to obtain an electrically neutral chemical formula for aluminum chloride, Al3+Cl-?
Cross over charges Reason: If you cross over the charges, the correct chemical formula would be produced, AlCl3.
Select all that apply Which of the following options correctly describe electronegativity? (Select all that apply.)
Electronegativity is a relative quantity. Electronegativity measures the ability of an atom in a covalent bond to attract the shared electron pair(s).
Select all that apply Which of the following options correctly describe the general trends in electronegativity? (Select all that apply.)
Electronegativity tends to decrease down a group of the periodic table. Metals tend to have lower electronegativities than nonmetals.
Electronegativity is the comparative ability of atoms of an element to attract bonding electrons.
Elements with higher values have the greatest attraction for bonding electrons, and elements with the lowest values have the least attraction for bonding electrons.
Select all that apply Which of the following options describe the correct format used to represent a chemical compound? (Select all that apply.)
If there is no subscript present for an atom in a compound, the subscript is assumed to be 1. The number of atoms and/or ions in the formula is indicated by a subscript.
Ionic bonds are formed when atoms transfer electrons to achieve the noble gas electron arrangement.
In general, ionic compounds are formed when a metal from the left side of the periodic table reacts with a nonmetal from the right side.
Select all that apply Which of the following statements correctly describe the bonding in the ionic compound KBr? (Select all that apply.)
Ionic bonds generally form when a metal reacts with a nonmetal. K loses an electron to form the ion K+. The attraction between oppositely charged ions is called the ionic bond.
Select all that apply Which of the following options correctly describe the physical properties of ionic compounds? (Select all that apply.)
Ionic compounds of the representative elements are generally crystalline solids. Ionic compounds that will dissolve in water produce a solution that will conduct an electric current.
Select all that apply Which of the following options are correct names for ionic compounds? (Select all that apply.)
Rubidium chloride Copper(II) sulfide
Select all that apply Consider the formula for the ionic compound AlCl3. Which of the following statements correctly interpret this formula? (Select all that apply.)
The compound contains one Al3+ ion for every three Cl- ions. The positive ion in the compound is Al3+.
Select all that apply Which of the following options correctly describe how to name an ionic compound? (Select all that apply.)
The positive ion is named first and the negative ion is named second. For single-charge nonmetal ions, the element name is changed to end in -ide.
Select all that apply Which of the following options correctly describe how to name a covalent compound? (Select all that apply.)
The second element is named with its root and the suffix -ide. A Greek numerical prefix is used to indicate the number of atoms of each element in the compound if the number of atoms is greater than 1. The name of the first element remains unchanged, except for the addition of a prefix where appropriate.
True or false: The amount of energy released to form a compound from its elements is the same as the amount of energy required when the same compound is decomposed to its elements.
True Reason: The law of conservation of energy states that energy is neither created nor lost but conserved.
chemical bond
an attractive force that holds atoms together in a compound. There are three general classes of chemical bonds: (1) ionic bonds, (2) covalent bonds, and (3) metallic bonds.
An easy way to produce the electrically neutral chemical formula for an ionic compound is to cross over the absolute _____ numbers and use them as _____.
charge; subscripts
Compounds are formed when atoms are held together by an attractive force called a
chemical bond
The absolute ______ of the electronegativity of two bonded atoms can be used to be predict the ______ of (the) bond.
difference; type
Electronegativity tends to _____ from left to right across a period of the periodic table and tends to _____ down a group.
increase; decrease
Elements combine in three general ways. In _____ compounds, electrons are transferred from one element to the other, whereas in _____ compounds, electrons are shared between atoms. Third, in _____ bonding, electrons are shared between a large number of atoms in an electron sea.
ionic; covalent; metallic
If energy is absorbed in a chemical reaction, then it appears on the ______ side of the reaction arrow in the chemical equation. If energy is released, it appears on the ______ side.
left; right Reason: If energy is absorbed, it can be considered a reactant and appears on the left side of the reaction arrow in a chemical equation. If energy is released, it can be considered a product and appears on the right side of the reaction arrow in a chemical equation.
When Al ionizes, it tends to _____ _____ electrons in order to achieve the same electron configuration as _____.
lose; 3; Ne
When naming an ionic compound, the _____ ion is always named first. To name the negative ion, the root of the element name is added to the suffix _____.
metal; -ide
When naming an ionic compound containing a polyatomic ion, the parent name of the ______ ion is named first and the parent name of the ______ ion is named second.
metal; polyatomic
The noble gases, like neon and helium, are unique, occurring as single atoms called
monatomic
When writing the chemical formula for an ionic compound containing a polyatomic ion, parentheses are included if ______ polyatomic ion is present. The subscript is included ______ the parentheses to indicate the number of polyatomic ions present.
more than one; outside
A covalent bond arises from the net attraction between the _____ of each atom and the electrons of the other, and results in electrons being _____ between the two atoms.
nucleus; shared
In the formation of ionic compounds, a metal will form ______ ions by ______ electrons, and a nonmetal will form ______ ions by ______ electrons.
positive; losing; negative; gaining
When writing out the chemical formula of an ionic compound, first write the symbol of the ______ ion and then the symbol of the ______ ion. Next include ______ to indicate the number of ions needed to produce a neutral compound.
positive; negative; subscripts
A chemical _____ involves the transformation of one substance to another by breaking and/or forming chemical bonds.
reaction
Ionic compounds are typically _____ at room temperature, and ones that will dissolve in water produce a solution that can conduct _____. (Use just one word per blank.)
solids; electricity
molecule
the smallest particle of a compound, or a gaseous element, that can exist and still retain the characteristic chemical properties of a substance
the number of electrons in the outermost orbital that usually determines the chemical properties of an atom
these outer electrons are called valence electrons; and it is the valence electrons that participate in chemical bonding
An ionic bond results when _____ charges attract. The elements involved in an ionic bond are typically a metal and a(n) _____
unlike; nonmetal
The most easily removed electrons from an atom are the ______ electrons.
valence
Elements combine to form ionic compounds by gaining or losing _____ electrons. The number of electrons lost must _____ the number of electrons gained in order to form a neutral compound.
valence; equal
Classify the following species as an element or a compound.
water- compound calcium- element
Potassium permanganate
The permanganate ion is MnO4-.
