Question 1

Which of the following best distinguishes an element from a compound?

Accepted Answer

An element consists of only one type of atom, while a compound consists of two or more types of atoms chemically bonded together.

Question 2

Which four elements make up approximately 96% of living matter?

Accepted Answer

C, H, O, N

Question 3

Given an atom with atomic number 8 and mass number 16, how many neutrons does it have?

Accepted Answer

8

Question 4

Which statement about isotopes is correct?

Accepted Answer

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

Question 5

How does the electron configuration of an atom influence its chemical behavior?

Accepted Answer

It determines the number and types of bonds the atom can form with other atoms.

Question 6

Which type of chemical bond involves the sharing of a pair of valence electrons between atoms?

Accepted Answer

Covalent bond

Question 7

A water molecule ($$\mathrm{H_2O}) is $$held together by which type of bond?

Accepted Answer

Covalent bond

Question 8

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 9

Which statement about van der Waals interactions is correct?

Accepted Answer

They are weak interactions that occur due to transient local partial charges.

Question 10

Which of the following is a consequence of the molecular shape of water?

Accepted Answer

Water molecules have a bent shape, leading to a polar molecule capable of hydrogen bonding.

Question 11

Which of the following best explains why ice floats on water?

Accepted Answer

Hydrogen bonds in ice create a lattice structure that is less dense than liquid water.

Question 12

Which chemical equation correctly summarizes the process of photosynthesis?

Accepted Answer

$$6\mathrm{CO_2$} + 6\mathrm{H_2O} \rightarrow \mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$}$$

Question 13

Which of the following is NOT a property of water resulting from hydrogen bonding?

Accepted Answer

Low boiling point

Question 14

A sodium atom ($$\mathrm{Na}) $$has an atomic number of 11. How many electrons does a neutral sodium atom have?

Accepted Answer

11

Question 15

Which of the following best describes a nonpolar covalent bond?

Accepted Answer

A bond in which electrons are shared equally between atoms.

Question 16

Which of the following is a trace element essential for humans but required only in minute amounts?

Accepted Answer

Iron (Fe)

Question 17

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons determine the chemical reactivity of an atom.

Question 18

Which of the following best explains the importance of molecular shape in biological function?

Accepted Answer

Molecular shape allows molecules to interact specifically with other molecules, such as enzymes binding to substrates.

Question 19

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

Accepted Answer

The bond between sodium and chlorine in table salt ($$\mathrm{NaCl})$$

Atoms, Molecules, and Chemical Bonds: Foundations of General Biology

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