ACS Principles of Chemistry I Final Review
Exam Questions and Answers
1.The number of neutrons in the 37/17 Cl- ion is
A. 17
B. 20
C. 21
D. 37:
ANS B. 20
2.An Argon atom is isoelectronic with
A. Cl
B. Ca
C. Ti4+
D. N3-:
ANS C. Ti4+
3.Which pair of particles has the same number of electrons?
A. F-, Mg2+
B. Ne, Ar
C. Br-, Se
D. Al3+, P3-:
ANS A. F-, Mg2+
,4.Which ion has twenty-six electrons?
A. Cr2+
B. Fe2+
C. Ni2+
D. Cu2+:
ANS C. Ni2+
5.Which statement is true?
A. The nucleus of an atoms contains neutrons and electrons.
B. The atomic number of an element is the number of protons in
one atom.
C. The mass number of an atom is the number of protons in the
nucleus plus the number of electrons outside.
D. The number if electrons outside the nucleus is the same as
the number of neutrons in the nucleus.:
ANS B. The atomic number of an element is the number of protons in
one atom.
6.In what respect does an atom of magnesium, Mg, differ from
a magnesium ion, Mg2+?
A. The ion has an inert gas electron configuration; the atom does
not.
B. The positive charge on the nucleus of the ion is two units
greater than the nuclear charge on the atom.
C. The ion has two more protons than the atom.
,D. The ion has two more planetary electrons than the atom.:
ANS A. The ion has an inert gas electron configuration; the atom does
not.
7.A sodium ion differs from a sodium atom in that the sodium ion:
A. has fever electrons.
B. is an isotope of sodium.
C. exists only in solution.
D. has a negative charge on its nucleus.:
ANS A. has fever electrons.
8.Which term best characterizes the relation of hydrogen to
deuterium?
A. allotropes
B. isomers
C. isotopes
D. polymers:
ANS C. isotopes
9.The element X occurs naturally to the extent 20.0% 12X and
80% 13X. The atomic mass of X is nearest:
A. 12.2
B. 12.5
C. 12.8
D. 13.0:
, ANS C. 12.8
10.In which pair are the two species both isoelectronic and
isotopic?
A. 40/20 Ca2+ & 40/18 Ar
B. 39/19 K+ & 40/19 K+
C. 24/12 Mg2+ & 25/12 Mg
D. 56/26 Fe2+ & 57/26 Fe 3+:
ANS B. 39/19 K+ & 40/19 K+
11.An atom of the element number 84 and mass number 199
emits an alpha particle. The residual atom after this change
has an atomic number of and a mass number of .
A. 82, 195
B. 84, 203
C. 85, 195
D. 86, 199:
ANS A. 82, 195
12.In effective nuclear changes by bombarding target nuclei
with positively charges alpha particles, it is necessary to
accelerate these particles to high speeds because it is
necessary to:
A. drive the positive particles through the electron cloud.
B. overcome the force of repulsion of the nucleus.
Exam Questions and Answers
1.The number of neutrons in the 37/17 Cl- ion is
A. 17
B. 20
C. 21
D. 37:
ANS B. 20
2.An Argon atom is isoelectronic with
A. Cl
B. Ca
C. Ti4+
D. N3-:
ANS C. Ti4+
3.Which pair of particles has the same number of electrons?
A. F-, Mg2+
B. Ne, Ar
C. Br-, Se
D. Al3+, P3-:
ANS A. F-, Mg2+
,4.Which ion has twenty-six electrons?
A. Cr2+
B. Fe2+
C. Ni2+
D. Cu2+:
ANS C. Ni2+
5.Which statement is true?
A. The nucleus of an atoms contains neutrons and electrons.
B. The atomic number of an element is the number of protons in
one atom.
C. The mass number of an atom is the number of protons in the
nucleus plus the number of electrons outside.
D. The number if electrons outside the nucleus is the same as
the number of neutrons in the nucleus.:
ANS B. The atomic number of an element is the number of protons in
one atom.
6.In what respect does an atom of magnesium, Mg, differ from
a magnesium ion, Mg2+?
A. The ion has an inert gas electron configuration; the atom does
not.
B. The positive charge on the nucleus of the ion is two units
greater than the nuclear charge on the atom.
C. The ion has two more protons than the atom.
,D. The ion has two more planetary electrons than the atom.:
ANS A. The ion has an inert gas electron configuration; the atom does
not.
7.A sodium ion differs from a sodium atom in that the sodium ion:
A. has fever electrons.
B. is an isotope of sodium.
C. exists only in solution.
D. has a negative charge on its nucleus.:
ANS A. has fever electrons.
8.Which term best characterizes the relation of hydrogen to
deuterium?
A. allotropes
B. isomers
C. isotopes
D. polymers:
ANS C. isotopes
9.The element X occurs naturally to the extent 20.0% 12X and
80% 13X. The atomic mass of X is nearest:
A. 12.2
B. 12.5
C. 12.8
D. 13.0:
, ANS C. 12.8
10.In which pair are the two species both isoelectronic and
isotopic?
A. 40/20 Ca2+ & 40/18 Ar
B. 39/19 K+ & 40/19 K+
C. 24/12 Mg2+ & 25/12 Mg
D. 56/26 Fe2+ & 57/26 Fe 3+:
ANS B. 39/19 K+ & 40/19 K+
11.An atom of the element number 84 and mass number 199
emits an alpha particle. The residual atom after this change
has an atomic number of and a mass number of .
A. 82, 195
B. 84, 203
C. 85, 195
D. 86, 199:
ANS A. 82, 195
12.In effective nuclear changes by bombarding target nuclei
with positively charges alpha particles, it is necessary to
accelerate these particles to high speeds because it is
necessary to:
A. drive the positive particles through the electron cloud.
B. overcome the force of repulsion of the nucleus.
