ORGANIC AND BIOCHEMISTRY, 12TH EDITION,
FREDERICK A. BETTELHEIM, WILLIAM H. BROWN,
MARY K. CAMPBELL, SHAWN O. FARRELL, OMAR
TORRES
What is an element?
A. A mixture of substances
B. A substance that can be broken down chemically
C. A substance that cannot be chemically broken down
D. A compound
Answer: C
Rationale: An element is the simplest form of matter and cannot be broken down into
simpler substances by chemical means.
What is an atom?
A. A type of molecule
B. The smallest part of an element that retains its identity
C. A charged particle
D. A chemical bond
Answer: B
Rationale: An atom is the smallest unit of an element that still maintains the properties of
that element.
Where are protons and neutrons located in an atom?
A. Electron cloud
B. Outer rings
C. Nucleus
D. Energy levels
Answer: C
Rationale: The nucleus is the central core of an atom where protons and neutrons are
found.
,Which particle has a positive charge?
A. Electron
B. Neutron
C. Proton
D. Molecule
Answer: C
Rationale: Protons carry a positive charge and are located in the nucleus.
How can the number of neutrons in an atom be determined?
A. Atomic number minus atomic mass
B. Atomic mass minus atomic number
C. Atomic number only
D. Number of electrons
Answer: B
Rationale: Neutrons = atomic mass − atomic number.
Where are electrons located?
A. Inside the nucleus
B. In the proton cloud
C. Outside the nucleus in energy levels
D. In the center of the atom
Answer: C
Rationale: Electrons occupy energy levels (shells) surrounding the nucleus.
What does the atomic number represent?
A. Number of neutrons
B. Total mass
C. Number of protons
D. Number of molecules
Answer: C
Rationale: The atomic number equals the number of protons and also equals the number of
electrons in a neutral atom.
What is atomic mass?
A. Number of electrons
,B. Total number of protons only
C. Total mass of protons and neutrons
D. Number of energy levels
Answer: C
Rationale: Atomic mass is the sum of protons and neutrons in the nucleus.
What is an energy level?
A. A chemical bond
B. A region where electrons are likely to be found
C. A type of atom
D. A proton shell
Answer: B
Rationale: Energy levels are regions around the nucleus where electrons are most likely
located.
Which property describes a metal?
A. Brittle and dull
B. Poor conductor
C. Shiny, ductile, and malleable
D. Gas at room temperature
Answer: C
Rationale: Metals are typically shiny, can be shaped (malleable), and drawn into wires
(ductile).
What does luster describe?
A. Strength of a material
B. Ability to conduct electricity
C. How a material reflects light
D. Its density
Answer: C
Rationale: Luster refers to the shininess or reflective quality of a material.
What does ductile mean?
A. Can be broken easily
B. Can be drawn into wires
, C. Cannot conduct heat
D. Has no shape
Answer: B
Rationale: Ductility is the ability to be stretched into thin wires.
What is a nonmetal?
A. Shiny and conductive
B. Malleable substance
C. Poor conductor and brittle
D. Always liquid
Answer: C
Rationale: Nonmetals lack metallic properties and are often brittle and poor conductors.
Which group is known as halogens?
A. Group 1
B. Group 17
C. Group 18
D. Group 2
Answer: B
Rationale: Halogens are reactive nonmetals found in Group 17 of the periodic table.
Which group is known as noble gases?
A. Group 16
B. Group 17
C. Group 18
D. Group 1
Answer: C
Rationale: Noble gases are stable, nonreactive elements in Group 18.
What is matter?
A. Energy only
B. Anything with mass and volume
C. Only solids
D. Only gases