Question 1

Which of the following statements best explains why sodium (Na) forms a cation (Na+) when it reacts with chlorine (Cl) to form table salt (NaCl)?

Accepted Answer

Sodium loses an electron, resulting in a positively charged ion with a full outer shell.

Question 2

A neutral atom of magnesium (Mg) has an atomic number of 12 and an atomic mass of 24. How many neutrons does it have?

Accepted Answer

12

Question 3

Which property of water allows it to move upward through the roots and stems of plants against gravity?

Accepted Answer

Adhesion

Question 4

Which of the following best describes an isotope?

Accepted Answer

An atom with a different number of neutrons than other atoms of the same element

Question 5

A solution has a pH of 3. Which of the following statements is true about this solution?

Accepted Answer

It is acidic and has a high concentration of H+ ions.

Question 6

Which of the following best explains why water is considered a 'universal solvent'?

Accepted Answer

Water molecules are polar, allowing them to surround and dissolve many ionic and polar substances.

Question 7

Which of the following chemical bonds is responsible for holding together the atoms in a molecule of oxygen gas (O2)?

Accepted Answer

Nonpolar covalent bond

Question 8

A student writes the following chemical equation: 2H2 + O2 → 2H2O. What does the coefficient '2' in front of H2O indicate?

Accepted Answer

Two molecules of water are produced in the reaction.

Question 9

Which of the following scenarios best illustrates the formation of an ionic bond?

Accepted Answer

A sodium atom transfers an electron to a chlorine atom, resulting in Na+ and Cl- ions that attract each other.

Question 10

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule is a group of atoms held together by covalent bonds, while a compound consists of two or more different elements bonded together.

Question 11

Which of the following best explains why water has a high specific heat capacity?

Accepted Answer

Hydrogen bonds between water molecules require more energy to break, allowing water to absorb more heat before changing temperature.

Question 12

A neutral atom of chlorine has 17 protons and 18 neutrons. What is its atomic mass?

Accepted Answer

35

Question 13

Which of the following is a real-life example of a hydrogen bond's importance?

Accepted Answer

The double-helix structure of DNA being stabilized by attractions between hydrogen and nitrogen or oxygen atoms.

Question 14

If an atom has 8 protons, 8 neutrons, and 10 electrons, what is its net charge?

Accepted Answer

-2

Question 15

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in partial charges on the atoms.

Question 16

A beaker contains a solution with a high concentration of OH- ions. Which of the following best describes the solution?

Accepted Answer

It is basic with a pH greater than 7.

Question 17

Which of the following best explains why noble gases (like neon and argon) are chemically unreactive?

Accepted Answer

Their outermost energy level is full, making them stable and unlikely to form bonds.

Question 18

Which of the following best describes the role of subscripts in a chemical formula?

Accepted Answer

They show the number of atoms of each element in a molecule.

Question 19

Which of the following is an example of a compound but not a molecule?

Accepted Answer

NaCl

Fundamentals of Atoms, Elements, and Chemical Bonds

Study Guide - Practice Questions