Explain the difference between a covalent-bond formed between two atoms of the same element and a covalent bond formed between atoms of two different elements.

Match the following physical and chemical properties with octane, $\mathrm{C}_8 \mathrm{H}_{18}$, found in gasoline, or magnesium sulfate, $\mathrm{MgSO}_4$, also called Epsom salts:

a. contains only covalent bonds

b. melts at $1124^{\circ} \mathrm{C}$

c. is insoluble in water

d. is a liquid at room temperature

e. is a strong electrolyte

Classify the following bond as ionic, polar covalent, or nonpolar covalent, and explain: the NB bond in $\mathrm{H}_3 \mathrm{NBCl}_3$

Predict the type of bond (ionic, covalent, or polar covalent) one would expect to form between the following pairs of elements. Ba and S

Explain the difference between a covalent bond formed between two atoms of the same element and a covalent bond formed between atoms of two different elements.

Predict the type of bond (ionic, covalent, or polar covalent) one would expect to form between the following pairs of elements. S and S

Classify the following bond as ionic, polar covalent, or nonpolar covalent, and explain: the $\mathrm{SiCl}$ bond in $\mathrm{Cl}_3 \mathrm{SiSiCl}_3$.

How many electrons are there in a double covalent bond?

Which of the substances CdBr$_2$, P$_4$, BrF$_3$, MgO, NF$_3$, BaCl$_2$,POCl$_3$, and LiBr are:

(a) largely ionic?

(b) nonpolar covalent?

(c ) polar covalent?

Which member of each of the following pairs of compounds would most likely contain covalent bonds?

a. $\text{Na}_2\text{O}$ or $\text{H}_2\text{O}$ b. $\text{SnO}_2$ or $\text{CO}_2$ c. BrCl or AlCl d. $\text{NH}_3$ or $\text{Mg}_2\text{N}_3$

Which of the following images represents a covalent compound?

Is the following statement true regarding a covalent bond between nitrogen and oxygen atoms in a nitric oxide, NO, molecule?

Energy is required to break a covalent bond.

Is the $\mathrm{H}-\mathrm{O}$ bond in water nonpolar covalent, polar covalent, or ionic? Define each term, and explain your choice.

If the electronegativity difference between 2 atoms is greater than 0.4 but less than 2.1 , a bond between them will
(a) be ionic. (b) be covalent and nonpolar. (c) be covalent and polar. (d) not form.