$\text{Mg}^{2+}$ has more protons, increasing the effective nuclear charge and pulling electrons closer.

Question 1

Which of the following best explains why atomic radius decreases across a period from left to right on the periodic table?

Accepted Answer

The effective nuclear charge increases, pulling electrons closer to the nucleus.

Question 2

Which of the following ions has the largest ionic radius?

Accepted Answer

$	ext{O}^{2-}$

Question 3

Which element has the highest first ionization energy?

Accepted Answer

$	ext{Ne}$

Question 4

Which of the following compounds contains both ionic and covalent bonds?

Accepted Answer

$	ext{NaNO}_3$

Question 5

What is the correct name for the compound $	ext{Fe}_2	ext{O}_3$?

Accepted Answer

Iron(III) oxide

Question 6

Which of the following best describes the trend in electronegativity across a period?

Accepted Answer

It increases due to increasing effective nuclear charge.

Question 7

Which of the following molecules is nonpolar?

Accepted Answer

$	ext{CO}_2$

Question 8

What is the formula for ammonium sulfate?

Accepted Answer

$	ext{(NH}_4)_2	ext{SO}_4$

Question 9

Which of the following best explains why $	ext{Mg}^{2+}$ has a smaller radius than $	ext{Na}^+$?

Accepted Answer

$	ext{Mg}^{2+}$ has more protons, increasing the effective nuclear charge and pulling electrons closer.

Question 10

Which of the following acids is correctly named?

Accepted Answer

$	ext{HNO}_3$ = Nitric acid

Question 11

Which of the following best describes the bonding in metallic solids?

Accepted Answer

Electrons are delocalized and move freely throughout the solid.

Question 12

Which of the following elements is most likely to form a cation?

Accepted Answer

$	ext{Na}$

Question 13

Which of the following best explains why fluorine is the most electronegative element?

Accepted Answer

It has a high effective nuclear charge and a small atomic radius.

Question 14

What is the correct formula for calcium phosphate?

Accepted Answer

$	ext{Ca}_3	ext{(PO}_4)_2$

Question 15

Which of the following statements about the shielding effect is correct?

Accepted Answer

The shielding effect increases down a group as more energy levels are added.

Question 16

Which of the following is the correct Lewis structure for carbon dioxide ($	ext{CO}_2$)?

Accepted Answer

O=C=O

Question 17

Which of the following best describes why ionic compounds tend to have high melting points?

Accepted Answer

They have strong electrostatic attractions between oppositely charged ions.

Question 18

Which of the following is the correct name for $	ext{N}_2	ext{O}_5$?

Accepted Answer

Dinitrogen pentoxide

Question 19

Which of the following best explains why the first ionization energy of sodium is much lower than that of chlorine?

Accepted Answer

Sodium's valence electron is farther from the nucleus and more shielded.

Question 20

Which of the following is the correct formula for aluminum hydroxide?

Accepted Answer

$	ext{Al(OH)}_3$

Unit 4: Element and Compound Properties – Periodic Trends, Bonding, and Nomenclature

Study Guide - Practice Questions