Biology Life on Earth 11th Edition by Audesirk - Test Bank - Updated

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) A substance with specific properties that cannot be broken down or converted into another

substance is called a(n)

A) compound.

B) molecule.

C) element.

D) mixture.

E) ion.

Answer: C

Chapter Section: 2.1

Learning Outcome: 2.1

2) If you examined the human body on a chemical composition basis, which of the following

combinations of elements would be most common?

A) O, C, P, S

B) O, C, N, Na

C) C, N, Ca, S

D) O, C, H, N

E) C, H, Ca, Cl

Answer: D

Chapter Section: 2.1

Learning Outcome: 2.1

3) The atomic number of an atom is defined as the

A) number of neutrons in the atomic nucleus.

B) total number of electrons and neutrons.

C) number of electrons in the outermost energy level.

D) total number of energy shells.

E) number of protons in the atomic nucleus.

Answer: E

Chapter Section: 2.1

Learning Outcome: 2.2

4) Phosphorus has an atomic number of 15, so what is the distribution of its electrons?

A) The first, second, and third energy levels have 5 electrons each.

B) The first energy level has 2, the second has 8, and the third has 5.

C) The first energy level has 8 and the second has 7.

D) The first energy level has 2 and the second has 13.

E) The electron arrangement cannot be determined from the atomic number alone.

Answer: B

Chapter Section: 2.1

Learning Outcome: 2.2

1)

2)

3)

4)

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

A) Carbon, phosphorus, hydrogen, sulfur

B) Carbon, oxygen, calcium, sulfur

C) Carbon, sodium, chlorine, magnesium

D) Oxygen, hydrogen, calcium, sodium

E) Carbon, hydrogen, nitrogen, oxygen

Answer: E

Chapter Section: 2.1

Learning Outcome: 2.2

6) Imagine that you have been hired as a chemist and your first task is to examine a newly discovered

atom. The paperwork you are given states that its atomic number is 110. What does this mean?

A) The atom contains 55 electrons.

B) The atom contains 110 protons.

C) The atom is an isotope.

D) The atom contains 55 protons and 55 neutrons.

Answer: B

Chapter Section: 2.1

Learning Outcome: 2.2

7) Iron is an important element in human body cells. If iron has an atomic number of 26, what does

this tell you about this element?

A) An iron atom is unable to become an isotope.

B) An iron atom has 13 electrons and 13 protons.

C) An iron atom has 26 protons.

D) An iron atom has 13 protons and 13 neutrons.

Answer: C

Chapter Section: 2.1

Learning Outcome: 2.2

8) Carbon-14 is often used for carbon dating, where scientists measure the rate of carbon-14 decay to

determine the age of items. Carbon-14 contains six protons and eight neutrons. During the process

of carbon-14 decay, one of its eight neutrons becomes a proton and an electron is emitted. Which

of the following is the best explanation of what has occurred?

A) The resulting atom has a more stable nucleus.

B) The resulting atom is still carbon-14.

C) An ionic bond has formed.

D) The resulting atom is now a different element because the number of protons has changed.

Answer: D

Chapter Section: 2.1

Learning Outcome: 2.3

9) Radioactive isotopes are biological tools that are often used to

A) measure the size of fossils.

B) detect brain tumors and other important medical technologies.

C) increase the pH of blood.

D) build up a store of calcium in a cell.

Answer: B

Chapter Section: 2.1

Learning Outcome: 2.3

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9)

210) For an atom to achieve maximum stability and