Chapter 9: Chemical Bonds

What is true of chemical reactions?

a chemical reaction is the process used to describe a chemical change; chemical bonds are broken and/or made during a chemical reaction

monatomic molecule

a molecule that consists of one atom

triatomic molecule

a molecule that consists of three of the same atom bound together

diatomic molecule

a molecule that consists of two of the same atom bound together

In a chemical reaction, energy is _____ if the products have more potential energy than the reactants. If energy is _____, then the products have less potential energy than the reactants.

absorbed; released

What statements are true about writing the chemical formula of an ionic compound form its chemical name?

add subscripts to indicate the number of ions needed to produce a neutral compound; include parentheses and a subscript outside the parentheses if there is more than one polyatomic ion in the compound

What correctly describes the formation of ionic bonds?

an ionic bond typical forms when a metal reacts with a nonmetal; an ionic bond results from the combination of positive and negative ions; an ionic bond results from the transfer of electrons

What is true of a covalent bond?

as two atoms form a covalent bond, the stability of the system increases; a stable covalent bond is formed through nucleus-electron attractions; if the two atoms in a covalent bond approach too closely they will repel each other

One of the common names for sodium bicarbonate is _____ soda, because it is used as a leavening agent in baked goods.

baking

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

A covalent compound is a compound that contains only covalent_____.

bonds

The number of _____ formed by a particular element is called its valence.

bonds

Elements combine to form compounds by making chemical _____, which are formed by gaining, losing, or sharing ______.

bonds; electrons

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

Washing soda is a ______ for sodium bicarbonate, based on one of its popular uses.

common name

Sugar is an example of a(n)_____whereas carbon is an example of a(n) _______.

compound; element

What are different names for ionic compounds:

copper(II) sulfide; rubidium chloride

C-C bond

covalent

Two atoms may bond by sharing electrons. This type of bond is called a(n) ____ bond.

covalent

Ionic compounds are typically ______ at room temperature, and ones that will dispel in water produce a solution that can conduct _____.

crystalline solids; electricity

The absolute____ of the electronegativity of two bonded atoms can be used to be predict the ____ of (the) bond.

difference; type

A molecule that has a positive and a negative pole is called a(n) _______.

dipole

The relative ability of a bonded atom to attract shared electron pairs is called its _____.

electronegativity

What correctly describes electronegativity?

electronegativity measures the ability of an atom in a covalent bond to attract the shared electron pair(s); electronegativity is a relative quantity

What is the term used to describe the amount of energy required/released when a compound is formed form its elements?

heat of formation

Electronegativity tends to _____ from left to right across a period of the periodic table and tends to ____ down a group.

increase; decrease

Na-F bond

ionic

What describes the physical properties of ionic compounds?

ionic compounds that will dissolve in water produce a solution that will conduct an electric current; ionic compounds of the representative elements are generally crystalline solids

Bonding between atoms in compounds is typically described in one of two ways: by treating the atoms in a molecule as ______ atoms with changes occurring in their outer valence shells, or by describing a new orbital formed upon combining atoms called a(n) _____ orbital.

isolated; molecular

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

When Al ionizes it tends to ____ _____ electrons in order to achieve the same electron configuration as _____.

lose; 3; Ne

Lithium iodide (Lil) is an ionic compound. The metal lithium ______ an electron to form the ion Li+ and the nonmetal iodine_____ an electron for form the ion. The ions are held together by ______ in a crystal lattice.

loses; gains; a strong electrostatic attraction

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

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 elements's symbol.

subscript; right

What is true about the difference in electronegativity of two bonded atoms?

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

What is true about the ions formed by transition elements?

the ions formed by some transition elements are not easily predicted from the periodic table; transition elements produce positive ions

What is true about writing the chemical formula of an ionic compound containing a polyatomic ion from its chemical name?

the metal (or ammonium) ion is written first in the chemical formula; a subscript of 1 is implied if no subscript is present in the chemical formula

What is true about the models used to describe bonding between atoms in a molecule?

the molecular orbital description considers that the bonding electrons belong to the whole molecule; the molecular orbital representation describes the formation of new orbitals upon bonding

What correctly describes the rules used to name an ionic compound containing a polyatomic ion?

the names and formulas of polyatomic ions are not found on the periodic table. They must be memorized or provided; the metal ion is named first by using the parent name of the metal

What correctly describes how to name an ionic compound?

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.

single bond

two atoms share one pair of electrons

triple bond

two atoms share three pairs of electrons

multiple bond

two atoms share two or three pairs of electrons

double bond

two atoms share two pairs of electrons

Hydrogen

valence of 1

Oxygen

valence of 2

Nitrogen

valence of 3

Carbon

valence of 4

The outermost electrons of an element are called the _____ electrons. The electrons that are in stable, fully occupied orbitals are called _____ electrons.

valence; inner

What happens when Ca ionizes?

when Ca ionizes it has the same electron configuration as Ar; when Ca ionizes it has a net charge of +2

mono-

1

di-

2

Solve for the chemical formula of dichloride pentoxide, CL _______O________.

2; 5

The covalently bonded species shown has _____ bonding pair(s) and ______ lone pair(s).

3; one

penta-

5

hexa-

6

hepta-

7

The number of covalent bonds formed by nonmetals is equal to______

8 minus the family number

What is true about electron transfer in ionic bond formation?

The number of electrons lost must equal the number of electrons gained by atoms when an ionic bond is formed.

What is true about the octet rule?

The octet rule states that atoms tend to try to achieve the same electron configuration as the closest noble gas.

An atom is the smallest unit of a(n)______ that can exist alone. When atoms are chemically _____ together they form a compound. The smallest particle of a compound is called a(n) ______.

element; bonded; molecules

The _____ number, on the periodic table, indicates the number of valence electrons an atom will gain or lose to achieve the same electron configuration as the nearest ____ gas.

family; noble

alkali and alkaline earth metals

form ions of the same charge as the family number

nonmetals

form ions with a charge equal to their family number minus 8

What is true about metallic bonds?

metallic bonds are formed in solid metals such as copper; metallic bonds are responsible for the high electrical conductivity of metals

The term ____ is not typically used to describe ionic solids due to the absence of discrete units in their crystal lattice structure.

molecule

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 is typically formed between two _____. This bond involves the _____ of one or more electron pairs between the two atoms.

nonmetals; sharing

A covalent bond arises from the net attraction between the _____ of each atom and the electrons of there other, and results in electrons being _____ between the two atoms.

nucleus; shared

The _____ rule states that when atoms bond they may gain, lose, or share electrons in order to attain an outer level containing 8 electrons.

octet

C-F bond

polar covalent

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 equal electron distribution.

polar; poles

An ion that contains two or more atoms bonded together but that has an overall charge is called a _____ ion. Many _____ compounds contain such species.

polyatomic; ionic

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 _______ in order to indicate the number of ions needed to produce a neutral compound.

positive; negative; subscripts

Many transition elements from _____ ions with ____ charges.

positive; variable

Chemical energy describes changes in internal _______ energy.

potential

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; one