Chemistry BM 3

According to the octet rule, a calcium atom has a tendency to

• lose one electron.

• lose two electrons.

• gain one electron.

• gain two electrons.

The melting points of ionic compounds are higher than the melting points of molecular compounds because

• ionic substances tend to vaporize at room temperature.

• ionic substances are brittle.

• attractive forces between ions are greater than the attractive forces between molecules.

• the numbers of positive and negative charges are equal in an ionic compound.

A covalent bond is formed when two atoms

• share an electron with each other.

• share one or more pairs of electrons with each other.

• gain electrons.

• gain and lose electrons.

Two atoms will likely form a polar covalent bond if the electronegativity difference is

• 0.1

• 1.0

• 2.5

• 4.0

As the electronegativity difference between bonded atoms decreases, the bond becomes more _______.

• covalent

• ionic

• metallic

• Both (b) and (c)

As atoms bond with each other, they _______.

• increase their potential energy, thus creating less stable arrangements of matter.

• decrease their potential energy, thus creating less stable arrangements of matter.

• increase their potential energy, thus creating more stable arrangements of matter.

• decrease their potential energy, thus creating more stable arrangements of matter.

Which type of hybrid orbitals do oxygen atoms form in water molecules?

• sp³

• sp²

• sp³²

• sp

Which type of bonding is characterized by overlapping orbitals that allow outer electrons of atoms to move about freely throughout the entire lattice?

• ionic

• covalent

• metallic

• multiple

Ionic bonds form as a result of the electrostatic attraction between _______.

• dipoles.

• electrons.

• ions.

• nuclei.

Use the table below to choose the pair of elements that will most likely have the greatest ionic character.

K 0.8

Br 2.8

N 3.0

S 2.5

• K & N

• K & S

• N & Br

• S & Br