Question 1

Which statement best explains why period 2 nonmetals must obey the octet rule when forming molecules?

Accepted Answer

Because their outermost shell can only hold a maximum of eight electrons, corresponding to the $2s^2 2p^6$ configuration.

Question 2

Which of the following elements is an exception to the octet rule and typically attains a duet configuration?

Accepted Answer

Helium

Question 3

What is the correct Lewis symbol for silicon (Si)?

Accepted Answer

Si with four dots around it, one on each side

Question 4

Which of the following best describes the basic unit of an ionic compound?

Accepted Answer

Formula unit

Question 5

When calcium reacts with chlorine to form an ionic compound, what is the correct formula for the resulting compound?

Accepted Answer

$CaCl_2$

Question 6

Which of the following statements about ionic solids is TRUE according to Lewis theory?

Accepted Answer

Ionic solids are hard and brittle because ions are locked in position within the crystal lattice.

Question 7

Why do ionic compounds conduct electricity when dissolved in water but not in the solid state?

Accepted Answer

Because ions are free to move in solution, allowing charge to flow.

Question 8

Which compound has the higher melting point, NaCl or MgO, and why?

Accepted Answer

MgO, because the ions have larger charges.

Question 9

What is lattice energy?

Accepted Answer

The energy released when a solid crystal forms from separate ions in the gas state.

Question 10

Which of the following metals has the same charge in all of its compounds?

Accepted Answer

Na

Question 11

What is the correct name for the compound $CaBr_2$?

Accepted Answer

Calcium bromide

Question 12

Which of the following is the correct formula for the compound formed between aluminum and oxygen?

Accepted Answer

$Al_2O_3$

Question 13

A transition metal forms two different cations. How is this indicated in the name of its ionic compound?

Accepted Answer

By using a Roman numeral in parentheses after the metal name to indicate its charge.

Question 14

What is the correct name for the compound $CuO$?

Accepted Answer

Copper(II) oxide

Question 15

Which of the following best describes the process of ionic bond formation between sodium and chlorine?

Accepted Answer

Sodium loses one electron to become $Na^+$, chlorine gains one electron to become $Cl^-$, and the ions attract each other.

Question 16

Which of the following is NOT a property predicted by Lewis theory for ionic solids?

Accepted Answer

They conduct electricity in the solid state.

Question 17

What is the empirical formula for the ionic compound formed between magnesium and nitrogen?

Accepted Answer

$Mg_3N_2$

Question 18

Which of the following best explains why the formation of most ionic compounds is exothermic?

Accepted Answer

The extra stability from the crystal lattice releases energy as lattice energy.

Question 19

What is the correct name for the compound $PbCl_4$?

Accepted Answer

Lead(IV) chloride

Question 20

Which of the following is the correct formula for chromium(III) bromide?

Accepted Answer

$CrBr_3$

lecture 15

Study Guide - Practice Questions