$$\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}$$

Question 1

Which of the following statements correctly describes an isotope?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 2

Sulfur has an atomic number of 16. What is the number of neutrons in the most common isotope of sulfur ($$^{32}S$$)?

Accepted Answer

16

Question 3

A radioactive isotope of sulfur contains 19 neutrons. What is its mass number?

Accepted Answer

35

Question 4

Which electron configuration correctly represents Magnesium ($$Mg) $$with atomic number 12?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$

Question 5

Which of the following best describes the bond formed between potassium and chlorine in potassium chloride ($$KCl$$)?

Accepted Answer

Ionic bond

Question 6

In the molecule $$KCl$$, which atom gains an electron during bond formation?

Accepted Answer

Chlorine

Question 7

Which of the following molecules contains a polar covalent bond?

Accepted Answer

$$H_2S$$

Question 8

What is the total number of electrons in a neutral atom of silicon ($$Si) $$with atomic number 14?

Accepted Answer

14

Question 9

Which of the following best explains why $$H_2S is a $$polar molecule?

Accepted Answer

Sulfur is more electronegative than hydrogen, creating a partial negative charge on sulfur.

Question 10

Which of the following atoms has the highest electronegativity?

Accepted Answer

Chlorine

Question 11

If a neutral atom of magnesium ($$Mg) $$loses two electrons, what is the resulting charge?

Accepted Answer

$$+2$$

Question 12

Which of the following best describes the electron arrangement in $$SiH_4$$?

Accepted Answer

Silicon shares electrons with four hydrogen atoms, forming four single covalent bonds.

Question 13

Which of the following is the correct formula for calculating the number of neutrons in an atom?

Accepted Answer

$$	ext{Number of neutrons} = 	ext{Mass number} - 	ext{Atomic number}$$

Question 14

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

Accepted Answer

Potassium

Question 15

What type of charge does chlorine acquire when it forms an ion in $$KCl$$?

Accepted Answer

Negative

Question 16

Which of the following best describes the difference between atomic number and mass number?

Accepted Answer

Atomic number is the number of protons; mass number is the sum of protons and neutrons.

Question 17

Which of the following molecules would you expect to have the greatest difference in electronegativity between its atoms?

Accepted Answer

$$KCl$$

Question 18

Which of the following is a correct statement about the electron shells of magnesium ($$Mg$$)?

Accepted Answer

Magnesium has electrons in the $$1s$$, $$2s$$, $$2p$$, and $$3s$$ shells.

Question 19

Which of the following best describes the charge distribution in $$H_2S$$?

Accepted Answer

Sulfur has a partial negative charge, and hydrogen has a partial positive charge.

Question 20

Which of the following is the correct electron configuration for silicon ($$Si) $$with atomic number 14?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^2$$

Practice Sheet Chapter 2 Elements

Study Guide - Practice Questions