Deck 2: The Chemical Basis of Life I: Atoms, Molecules, and Water

Question 1

These are the smallest functional units of matter that form all chemical substances and that cannot be further broken down by ordinary chemical or physical means.

A) protons
B) neutrons
C) electrons
D) atoms
E) molecules

Answer 1

atoms

Question 2

Which of the following represents the smallest functional unit of living organisms?

A) atoms
B) molecules
C) proteins
D) water
E) salt

Answer 2

atoms

Question 3

Oxygen has an atomic mass of 16 and an atomic number of 8.

A) Oxygen has 16 neutrons.
B) Oxygen has 8 electrons.
C) Oxygen can form two bonds with other atoms.
D) Oxygen has 16 neutrons and 8 electrons.
E) Oxygen has 8 electrons and can form two bonds with other atoms.

Answer 3

Oxygen has 8 electrons and can form two bonds with other atoms.

Question 4

Ernest Rutherford's key experiment on alpha particle bombardment of gold foil was important to the development of

A) detection methods for protons.
B) alpha particle emitters.
C) gold as an element.
D) the modern model for atomic structure.
E) the concept that atoms have a homogenous distribution of protons throughout the atom.

Question 5

If a scientist were to shoot protons through an atom, for instance like Rutherford did with gold foil, he or she would likely find that

A) most of the protons passed straight through the atom.
B) few of the protons passed straight through the atom.
C) most of the protons deflected or bounced back from the atom.
D) most of the protons would be absorbed by the atom.
E) All of the choices are correct.

Question 6

If carbon has an atomic mass of 12 and an atomic number of 6 then it has

A) 6 electrons.
B) 12 electrons.
C) 18 electrons.
D) as many as 6 but no more than 12.
E) None of the choices are correct.

Question 7

Isotopes are different forms of the same element that

A) differ in their number of neutrons.
B) have the same numbers of protons.
C) are often used in medicine to track biological processes.
D) can be found in nature.
E) All the choices are correct.

Question 8

Which of the following represents an abundant element found in living organisms?

A) calcium.
B) iron.
C) iodine.
D) hydrogen.
E) sodium.

Question 9

Which of the following represents an ion?

A) Ca²⁺
B) He
C) H₂
D) CO₂
E) KCl

Question 10

This is formed when an atom loses an electron to another atom.

A) polar covalent bond
B) cations and anions that can form ionic bonds
C) covalent bond
D) hydrogen bond
E) nonpolar covalent bond

Question 11

Which of the following is TRUE of a chemical reaction?

A) It requires no energy.
B) It rarely occurs with a catalyst present.
C) It changes a substance from one form to another.
D) It is limited to only a few types of organisms.
E) They are usually irreversible.

Question 12

Which of the following is LEAST hydrophilic?

A) Na⁺
B) HCO3^-
C) oil
D) amphipathic molecules
E) CO₂

Question 13

Which of the following is not true of water?

A) It is polar.
B) It has a high heat of vaporization.
C) It has cohesive properties.
D) Its evaporation helps regulate body temperature.
E) It is a relatively poor solvent.

Question 14

pH buffers

A) minimize fluctuations in the pH of solutions.
B) are usually weak acids and bases.
C) are common in biological fluids.
D) limit major shifts in the amount of H⁺ and OH^- in solution.
E) All of the choices are correct.

Question 15

If one were to add a strong acid like HCl to an aqueous solution, which would result?

A) H⁺ would be released into solution.
B) The pH would increase.
C) The pH would decrease.
D) Both H⁺ would be released into solution and the pH would increase.
E) Both H⁺ would be released into solution and the pH would decrease.

Question 16

Which is true about a pH buffer?

A) It increases the amount of H⁺ in an acidic solution.
B) It reduces the amount of H⁺ in an acidic solution.
C) It reduces the amount of H⁺ in an alkaline solution.
D) It increases the amount of OH^- ions in an alkaline solution.
E) It reduces the amount of OH^- in an acidic solution.

Question 17

Considering solutions with the following pH, which is alkaline?

A) 8
B) 7
C) 6
D) 5
E) All are alkaline.

Question 18

The presence of salt helps prevent oceans from freezing.

Question 19

Buffers minimize fluctuations in the pH of a solution.