Question 1

Which of the following statements best explains why noble gases are generally unreactive?

Accepted Answer

They have a full valence shell with eight electrons, making them stable according to the octet rule.

Question 2

How many electrons can be held in the third energy level ($$n = 3) of an $$atom?

Accepted Answer

$$18$$

Question 3

Which of the following ions is isoelectronic with neon ($$Ne$$)?

Accepted Answer

$$Na^+$$

Question 4

A magnesium atom ($$Mg) $$loses two electrons to form an ion. What is the formula and charge of this ion?

Accepted Answer

$$Mg^{2+}$$

Question 5

Which of the following correctly describes the formation of an ionic bond?

Accepted Answer

A metal transfers electrons to a nonmetal, resulting in oppositely charged ions that attract each other.

Question 6

What is the correct formula for the ionic compound formed between aluminum ($$Al^{3+}) $$and oxide ($$O^{2-}) $$ions?

Accepted Answer

$$Al_2O_3$$

Question 7

Which of the following is the correct name for $$FeCl_3$$?

Accepted Answer

Iron(III) chloride

Question 8

How many covalent bonds does a nitrogen atom typically form to satisfy the octet rule?

Accepted Answer

$$3$$

Question 9

Which of the following compounds is covalent?

Accepted Answer

$$CO_2$$

Question 10

What is the correct name for the compound $$N_2O_5$$?

Accepted Answer

Dinitrogen pentoxide

Question 11

Which of the following ions is a polyatomic ion commonly found in antacids?

Accepted Answer

$$CO_3$$^{2-}$$ \, (carbonate)

Question 12

A patient is prescribed calcium phosphate as a supplement. What is the correct formula for calcium phosphate?

Accepted Answer

$$Ca_3$$($$PO_4)_2$

Question 13

Which of the following best describes the difference between ionic and covalent compounds?

Accepted Answer

Ionic compounds are formed from metals and nonmetals, while covalent compounds are formed from only nonmetals.

Question 14

What is the correct Lewis structure for methane ($$CH_4$$)?

Accepted Answer

A central carbon atom with four single bonds to four hydrogen atoms.

Question 15

Which of the following is the correct formula for dinitrogen trioxide?

Accepted Answer

$$N_2O_3$$

Question 16

A chloride ion ($$Cl^-) $$has:

Accepted Answer

17 protons and 18 electrons

Question 17

Which of the following best describes the charge on a sulfide ion ($$S^{2-}$$)?

Accepted Answer

It has gained two electrons and has a $$2-$$ charge.

Question 18

Which of the following is the correct name for $$P_2O_5$$?

Accepted Answer

Diphosphorus pentoxide

Question 19

Which of the following ions is responsible for regulating fluid balance outside cells in the human body?

Accepted Answer

$$Na^+$$

Question 20

What is the correct formula for the ionic compound formed between potassium ($$K^+) $$and sulfate ($$SO_4$$^{2-}$$)?

Accepted Answer

$$K_2SO_4$$

Compounds—How Elements Combine (Chapter 3 Study Notes)

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