1. The atomic weight of a newly discovered el-
ement is 98.225 amu. It has two naturally
occuring isotopes. One isotope has a mass of
96.780 amu. The second isotope has a per-
cent abundance of 41.7%. What is the mass
of the second isotope? Answer in units of amu.
2. Which of the following is a set of allotropes of
the same element?
a) O2, O3
b) graphite, tungsten carbide
c) water, ice
d) aluminum, aluminum oxide
e) NO, NO2, N2O
3. Elemental exonium (not a real element) con-
sists of two major isotopes
Abundance Mass
10% 96 amu
90% 110 amu
What is the atomic weight for exonium? An-
swer in units of amu.
4. Give the nuclide symbol for an atom that has
mass number 64 and 35 neutrons.
a) 64/35 Br
b) 29/64 Cu
c) 35/64 Gd
d) 99/35 Br
e) 35/64 Cu
f) 99/64 Gd
g) 64/35 Cu
h) 29/64 Gd
i) 64/29 Cu
j) 35/29 Br
5. There are three naturally occurring isotopes
of the hypothetical element hilarium 48Hi,
49Hi, and 51Hi. The percentages of these
isotopes are the following:
Hilarium Natural
Isotopes Abundance
48Hi 25.3%
49Hi 39.4%
51Hi 35.3%
You can assume that the atomic masses are
exactly equal to the mass number. Calculate
the weight of “naturally” occurring hilarium
and report it as you would for any other nat-
urally occurring element. Answer in units of g/mol.
6. How many protons are present in one cop-
per(II) ion?
7. Which of the following species has the greatest
number of electrons?
a) Cu^2+
b) Ni^3+
c) Ca^2+
d) Mn
e) Ti^2−
*That may be a lot of problems, but please understand that I'm entering A.P Chemistry. It would be appreciated for your help. Thank you!
ement is 98.225 amu. It has two naturally
occuring isotopes. One isotope has a mass of
96.780 amu. The second isotope has a per-
cent abundance of 41.7%. What is the mass
of the second isotope? Answer in units of amu.
2. Which of the following is a set of allotropes of
the same element?
a) O2, O3
b) graphite, tungsten carbide
c) water, ice
d) aluminum, aluminum oxide
e) NO, NO2, N2O
3. Elemental exonium (not a real element) con-
sists of two major isotopes
Abundance Mass
10% 96 amu
90% 110 amu
What is the atomic weight for exonium? An-
swer in units of amu.
4. Give the nuclide symbol for an atom that has
mass number 64 and 35 neutrons.
a) 64/35 Br
b) 29/64 Cu
c) 35/64 Gd
d) 99/35 Br
e) 35/64 Cu
f) 99/64 Gd
g) 64/35 Cu
h) 29/64 Gd
i) 64/29 Cu
j) 35/29 Br
5. There are three naturally occurring isotopes
of the hypothetical element hilarium 48Hi,
49Hi, and 51Hi. The percentages of these
isotopes are the following:
Hilarium Natural
Isotopes Abundance
48Hi 25.3%
49Hi 39.4%
51Hi 35.3%
You can assume that the atomic masses are
exactly equal to the mass number. Calculate
the weight of “naturally” occurring hilarium
and report it as you would for any other nat-
urally occurring element. Answer in units of g/mol.
6. How many protons are present in one cop-
per(II) ion?
7. Which of the following species has the greatest
number of electrons?
a) Cu^2+
b) Ni^3+
c) Ca^2+
d) Mn
e) Ti^2−
*That may be a lot of problems, but please understand that I'm entering A.P Chemistry. It would be appreciated for your help. Thank you!