Question 1

Which of the following best describes a compound?

Accepted Answer

A pure substance made up of two or more different kinds of atoms chemically bonded together.

Question 2

Which element is NOT found in significant amounts in the human body?

Accepted Answer

Fluorine (F)

Question 3

How many nitrogen (N) atoms are present in two molecules of caffeine ($$\mathrm{C_8H_{10}N_4O_2}$$)?

Accepted Answer

8

Question 4

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 5

A neutral atom of technetium-99 ($$^{99}_{43}\mathrm{Tc}) $$contains how many protons, neutrons, and electrons?

Accepted Answer

43 protons, 56 neutrons, 43 electrons

Question 6

Which of the following numbers are identical for the neutral isotopes carbon-12 and carbon-14?

Accepted Answer

Atomic number, number of protons, number of electrons

Question 7

How many valence electrons does a neutral atom of calcium (Ca) have?

Accepted Answer

Two

Question 8

Which element is expected to have chemical properties most similar to calcium (Ca)?

Accepted Answer

Magnesium (Mg)

Question 9

Which of the following elements has the largest atomic size?

Accepted Answer

Magnesium (Mg)

Question 10

Which of the following elements has the greatest ionization energy?

Accepted Answer

Fluorine (F)

Question 11

According to the octet rule, how many more electrons does sulfur (S) need to fill its valence shell?

Accepted Answer

2

Question 12

How many covalent bonds does sulfur (S) typically form to fill its octet?

Accepted Answer

2

Question 13

What ion is potassium (K) most likely to form?

Accepted Answer

$$\mathrm{K^+}$$

Question 14

Which of the following is a polyatomic ion commonly found in biological systems?

Accepted Answer

$$\mathrm{SO_4$^{2-}}$$

Question 15

What is the correct formula for the binary ionic compound formed between calcium (Ca) and oxygen (O)?

Accepted Answer

$$\mathrm{CaO}$$

Question 16

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

Accepted Answer

They have a full valence shell of 8 electrons.

Question 17

Which property increases as you move from left to right across a period in the periodic table?

Accepted Answer

Ionization energy

Question 18

Which of the following is the best definition of a cation?

Accepted Answer

An ion with more protons than electrons

Question 19

Which of the following is the correct Lewis symbol for sulfur (S)?

Accepted Answer

S with 6 dots

Question 20

Which of the following best describes the trend in metallic character on the periodic table?

Accepted Answer

It increases from top to bottom and from right to left.

Building Blocks of Molecules: Matter, Atoms, Elements, and the Periodic Table

Study Guide - Practice Questions