3) Exams Questions Expertly Solved
Different atomic forms of an element contain the same number of protons but a different number of
neutrons. What are these different atomic forms called? - A: ions Answer: B
B: isotopes
C: neutronic atoms
D: isomers
E: radioactive atoms
From its atomic number of 15, it is possible to predict that the phosphorus atom has - A: 15 neutrons.
Answer: E
B: 15 protons.
C: 15 electrons
D: 8 electrons in its outermost electron shell.
E: 15 protons and 15 electrons.
Which of the following statements best distinguishes hypotheses from theories in science? - Answer: C
A: Theories are hypotheses that have been proved.
B: Hypotheses are guesses; theories are correct answers.
C: Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.
D: Hypotheses and theories are essentially the same thing.
E: Theories are proved true in all cases; hypotheses are usually falsified by tests.
Each element is unique and different from other elements because of the number of protons in the
nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus? - A:
atomic mass Answer: C
B: atomic weight
C: atomic number
D: mass weight
, E: mass number
Which of the following statements correctly defines a kilocalorie? - Answer: D
A: the amount of heat required to raise the temperature of 1 g of water by 1°F
B: the amount of heat required to raise the temperature of 1 g of water by 1°C
C: the amount of heat required to raise the temperature of 1 kg of water by 1°F
D: the amount of heat required to raise the temperature of 1 kg of water by 1°C
E: the amount of heat required to raise the temperature of 1,000 g of water by 1°F
Which of the following statements is false?
(Chapters 1-3) - Answer: E
A: Atoms of the various elements differ in their number of subatomic particles.
B: All atoms of a particular element have the same number of protons in their nuclei.
C: The neutrons and protons present in the nucleus of an atom are almost identical in mass; each has a
mass of about 1 dalton.
D: An atom is the smallest unit of an element that still retains the properties of the element.
E: Protons and electrons are electrically charged particles. Protons have one unit of negative charge, and
electrons have one unit of positive charge.
Which of the following explains most specifically the attraction of water molecules to one another? - A:
nonpolar covalent bond Answer: D
B: polar covalent bond
C: ionic bond
D: hydrogen bond
E: hydrophobic interaction
Why is it important that an experiment include a control group? - Answer: E
A: The control group is the group that the researcher is in control of; it is the group in which the
researcher predetermines the nature of the results.
B: The control group provides a reserve of experimental subjects.