Question 1

Which subatomic particle is responsible for the atomic number of an element?

Accepted Answer

Proton

Question 2

Carbon-14 is used in radiometric dating because it is a radioactive isotope. Which of the following statements best describes a radioactive isotope?

Accepted Answer

Its nucleus spontaneously decays, giving off energy and particles.

Question 3

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic mass?

Accepted Answer

$$16$$

Question 4

Which property of water allows insects to walk on its surface?

Accepted Answer

Surface tension due to cohesion

Question 5

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

Accepted Answer

Covalent bond

Question 6

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

Accepted Answer

Hydrogen bonds between water molecules require much energy to break.

Question 7

A solution has a pH of 4. How many times more acidic is it than a solution with pH 6?

Accepted Answer

$$100$$ times

Question 8

Which of the following is true about ionic bonds?

Accepted Answer

They result from the attraction between oppositely charged ions.

Question 9

Which property of water is most important for the transport of nutrients in plants?

Accepted Answer

Cohesion and adhesion leading to capillary action

Question 10

What is the main difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

Polar covalent bonds have unequal sharing of electrons due to differences in electronegativity.

Question 11

Which of the following best describes a buffer in biological systems?

Accepted Answer

A compound that resists changes in pH by accepting or donating H+ ions.

Question 12

Which of the following is a correct representation of the dissociation of water?

Accepted Answer

$$\mathrm{H_2O} \rightarrow \mathrm{H^+} + \mathrm{OH^-}$$

Question 13

Which of the following statements about carbon is true and explains its central role in organic compounds?

Accepted Answer

Carbon can form four covalent bonds, allowing for diverse structures.

Question 14

Which process joins monomers to form polymers in biological systems?

Accepted Answer

Dehydration synthesis

Question 15

A molecule with the formula $$\mathrm{C_6H_{12}O_6$}$$ can exist as glucose or fructose. What term describes this relationship?

Accepted Answer

Isomers

Question 16

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

Accepted Answer

Hydrogen bonds in ice create a lattice that spaces molecules farther apart.

Question 17

Which of the following is NOT a property of water that makes it essential for life?

Accepted Answer

Ability to dissolve nonpolar substances

Question 18

Which of the following best describes the role of water in chemical reactions within organisms?

Accepted Answer

Water can act as a reactant, product, or solvent in chemical reactions.

Question 19

Which of the following is a correct description of a monomer?

Accepted Answer

A small molecule that can be joined to others to form a polymer.

Question 20

Which of the following best explains the function of the bicarbonate/carbonic acid buffer system in human blood?

Accepted Answer

It maintains blood pH by neutralizing excess acids and bases.

Chemical Basis of Life: Atoms, Elements, Isotopes, and Water

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