Question 1

Which subatomic particle determines the chemical reactivity of an element?

Accepted Answer

Electron

Question 2

An atom has 7 protons, 7 neutrons, and 7 electrons. What is its atomic number and what element is it?

Accepted Answer

Atomic number 7, Nitrogen

Question 3

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of one or more pairs of electrons between atoms

Question 4

How many electrons can the second electron shell of an atom hold?

Accepted Answer

$$8$$

Question 5

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 6

What type of bond is primarily responsible for holding the two strands of DNA together?

Accepted Answer

Hydrogen bonds

Question 7

A sodium atom loses one electron to become a sodium ion. What is the charge of the resulting ion?

Accepted Answer

$$+1$$

Question 8

Which of the following elements is most abundant in living cells?

Accepted Answer

Oxygen

Question 9

Which of the following best explains why water molecules are polar?

Accepted Answer

Oxygen is more electronegative than hydrogen, causing unequal sharing of electrons

Question 10

What is the maximum number of electrons that can occupy a single orbital?

Accepted Answer

$$2$$

Question 11

Which of the following is a real-life example of an ionic bond?

Accepted Answer

The bond between sodium and chlorine in table salt

Question 12

Which statement about valence electrons is correct?

Accepted Answer

Valence electrons determine the chemical behavior of an atom

Question 13

A carbon atom has an atomic number of 6. How many protons, neutrons (in $$^{12}C$$), and electrons does it have?

Accepted Answer

6 protons, 6 neutrons, 6 electrons

Question 14

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom in one molecule and an electronegative atom in another molecule

Question 15

Which of the following is true about nonpolar covalent bonds?

Accepted Answer

Electrons are shared equally between atoms

Question 16

Which of the following is a consequence of hydrogen bonding in water?

Accepted Answer

Water has a high surface tension

Question 17

If an atom has a filled outermost electron shell, it is most likely to be:

Accepted Answer

Inert

Question 18

Which of the following best explains why enzymes are needed to break covalent bonds in biological systems?

Accepted Answer

Covalent bonds are strong and require significant energy to break

Question 19

Which of the following is a trace element essential for life?

Accepted Answer

Iron

Question 20

Which of the following best describes the relationship between atomic number and the periodic table?

Accepted Answer

Atomic number increases from left to right across a period

Basic Chemistry for Biology: Atoms, Elements, and Chemical Bonds

Study Guide - Practice Questions