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

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

Question 1

Which subatomic particle is responsible for the positive charge of an atom's nucleus?

Accepted Answer

Proton

Question 2

Calcium (Ca) has an atomic number of 20 and an atomic mass of approximately 40.08. How many neutrons does a typical atom of calcium contain?

Accepted Answer

$$20.08$$

Question 3

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by transferring electrons from one atom to another

Question 4

What happens to the particles in a solid when it is heated and changes to a liquid?

Accepted Answer

They move more freely and slide past each other

Question 5

Which equation correctly represents the neutralization reaction between hydrochloric acid ($$\mathrm{HCl}) $$and sodium hydroxide ($$\mathrm{NaOH}$$)?

Accepted Answer

$$\mathrm{HCl} + \mathrm{NaOH} \rightarrow \mathrm{NaCl} + \mathrm{H}_2\mathrm{O}$$

Question 6

A student mixes an acid with a base and measures the temperature increase. What type of reaction is this?

Accepted Answer

Exothermic

Question 7

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements are arranged by increasing atomic number

Question 8

Which of the following is a property of bases?

Accepted Answer

They feel slippery

Question 9

If a gas is compressed at constant temperature, what happens to its pressure according to Boyle's Law?

Accepted Answer

Pressure increases

Question 10

Which of the following best explains why ionic compounds like sodium chloride ($$\mathrm{NaCl}) $$have high melting points?

Accepted Answer

They have strong electrostatic attractions between ions

Question 11

A sample of water is heated from $$25^\circ\mathrm{C} to$$ $$100^\circ\mathrm{C}. $$Which state change occurs at $$100^\circ\mathrm{C}$$ under normal atmospheric pressure?

Accepted Answer

Liquid to gas

Question 12

Which of the following is true about electrons in a covalent bond?

Accepted Answer

They are shared between atoms

Question 13

Which of the following is a real-life example of an exothermic reaction?

Accepted Answer

Combustion of gasoline in a car engine

Question 14

A solution has a pH of 3. Which of the following statements is correct?

Accepted Answer

The solution is acidic

Question 15

Which of the following best describes plasma, the fourth state of matter?

Accepted Answer

A state where particles are free-moving ions and electrons

Question 16

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

Accepted Answer

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

Question 17

Which of the following best describes what happens during a chemical reaction?

Accepted Answer

Atoms are rearranged to form new substances

Question 18

Which of the following is a common misconception about acids?

Accepted Answer

Acids always taste bitter

Question 19

Which of the following best explains why water is a liquid at room temperature while oxygen is a gas?

Accepted Answer

Water forms hydrogen bonds, which are stronger than the forces between oxygen molecules

Question 20

A chemist observes that a reaction absorbs heat from the surroundings. Which of the following best describes this reaction?

Accepted Answer

Endothermic

General Chemistry: Foundations and Key Concepts

Study Guide - Practice Questions

Study Guide - Flashcards