Question 1

Which of the following elements is NOT one of the four most common elements found in living organisms?

Accepted Answer

Phosphorus

Question 2

Trace elements are required by living organisms in small amounts. Which of the following is a trace element essential for thyroid hormone production?

Accepted Answer

Iodine

Question 3

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 4

How are electrons distributed in the electron shells of an atom with atomic number 10?

Accepted Answer

2 in the first shell, 8 in the second shell

Question 5

Which type of chemical bond involves the sharing of electron pairs between atoms?

Accepted Answer

Covalent bond

Question 6

A water molecule ($\mathrm{H_2O}$) is described as polar. What does this mean?

Accepted Answer

It has an uneven distribution of charge, with partial positive and negative regions

Question 7

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom

Question 8

Which interaction is responsible for the temporary attraction between molecules due to fluctuating electron distributions?

Accepted Answer

Van der Waals interaction

Question 9

What is the molecular formula for glucose, a common biological molecule?

Accepted Answer

$\mathrm{C_6H_{12}O_6}$

Question 10

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have different numbers of neutrons

Question 11

A sodium atom ($\mathrm{Na}$) loses one electron to become a sodium ion ($\mathrm{Na^+}$). What type of ion is this?

Accepted Answer

Cation

Question 12

Which property of an atom most directly determines its ability to form hydrogen bonds?

Accepted Answer

Electronegativity

Question 13

Why is the shape of a molecule important in biological systems?

Accepted Answer

It affects how the molecule interacts with other molecules

Question 14

Which of the following best describes a chemical reaction?

Accepted Answer

A process in which reactants are converted into products by rearranging chemical bonds

Question 15

If an atom has an atomic number of 8 and a mass number of 16, how many neutrons does it have?

Accepted Answer

8

Question 16

Which of the following is a compound?

Accepted Answer

Water ($\mathrm{H_2O}$)

Question 17

Which of the following best explains why ionic bonds form between sodium and chlorine atoms?

Accepted Answer

Sodium donates an electron to chlorine, resulting in oppositely charged ions that attract each other

Question 18

Which of the following is true about valence electrons?

Accepted Answer

They determine the chemical reactivity of an atom

Question 19

A molecule has the formula $\mathrm{C_2H_6O}$. Which of the following is a possible name for this molecule?

Accepted Answer

Ethanol

Question 20

Which of the following statements about chemical reactions is correct?

Accepted Answer

Chemical reactions involve the breaking and forming of chemical bonds

Study Guide: Basic Chemistry for Biology (Atoms, Bonds, and Molecules)

Study Guide - Practice Questions