Ch-8 review

Which is a typical characteristic of an ionic compound?Electron pairs are shared among atoms.The ionic compound has a low solubility in

water.The ionic compound is described as a

molecule.The ionic compound has a high melting point.

The ionic compound has a high melting point.

What is shown by the structural formula of a molecule or polyatomic ion?the arrangement of bonded atomsthe number of metallic bondsthe number of ionic bondsthe shapes of molecular orbitals

the arrangement of bonded atoms

Which of these elements does not exist as a diatomic molecule?

NeHFI

Ne

How do atoms achieve noble-gas electron configurations in single covalent bonds?One atom completely loses two electrons to

the other atom in the bond.Two atoms share two pairs of electrons.Two atoms share two electrons.Two atoms share one electron.

Two atoms share two electrons.

Why do atoms share electrons in covalent bonds?

to become ions and attract each otherto attain a noble-gas electron configurationto become more polarto increase their atomic numbers

to attain a noble-gas electron configuration

Which of the following elements can form diatomic molecules held together by triple covalent bonds?

carbonfluorineoxygennitrogen

nitrogen

Which noble gas has the same electron configuration as the oxygen in a water molecule?heliumargonneonxenon

neon

Which elements can form diatomic molecules joined by a single covalent bond?hydrogen onlyhalogens onlyhalogens and members of the oxygen group

onlyhydrogen and the halogens only

hydrogen and the halogens only

Which of the following is the name given to the pairs of valence electrons that do not participate in bonding in diatomic oxygen molecules?

unvalenced pairinner pairouter pairunshared pair

unshared pair

A molecule with a single covalent bond is ____.CO2

COCl 2

N 2

Cl 2

Once formed, how are coordinate covalent bonds different from other covalent bonds?

They are stronger.They are weaker.They are more ionic in character.There is no difference.

There is no difference.

When H forms a bond with H2 O to form the hydronium ion H 3O +, this bond is called a coordinate covalent bond because ____.

both bonding electrons come from the oxygen atom

it forms an especially strong bondthe electrons are equally sharedthe oxygen no longer has eight valence

electrons

both bonding electrons come from the oxygen atom

How many valid electron dot formulas—having the same number of electron pairs for a molecule or ion—can be written when a resonance structure occurs?

02 only1 only2 or more

0

How many electrons can occupy a single molecular orbital?

0214

2

According to VSEPR theory, molecules adjust their shapes to keep which of the following as far apart as possible?

pairs of valence electronsmobile electronsinner shell electronsthe electrons closest to the nuclei

pairs of valence electrons

What causes water molecules to have a bent shape, according to VSEPR theory?

repulsive forces between unshared pairs of electrons

interaction between the fixed orbitals of the unshared pairs of oxygen

ionic attraction and repulsionthe unusual location of the free electrons

repulsive forces between unshared pairs of electrons

What type of hybrid orbital exists in the methane molecule?

spsp 3

sp 2

sp 3d 2

sp 3

What is the shape of a molecule with a triple bond?tetrahedralbentpyramidallinear

linear

What is thought to cause the dispersion forces?attraction between ionssharing of electron pairsmotion of electronsdifferences in electronegativity

motion of electrons

What are the weakest attractions between molecules?ionic forcescovalent forcesVan der Waals forceshydrogen forces

Van der Waals forces

What causes hydrogen bonding?

attraction between ionsmotion of electronssharing of electron pairsbonding of a covalently bonded hydrogen

atom with an unshared electron pair

bonding of a covalently bonded hydrogen atom with an unshared electron pair