CW Atomic Structure Practice 3.doc - CW: Atomic Structure...

Name: _________________________________________ TP: _______
Directions: Answer the following questions directly on this sheet. Try your best to answer questions without
the use of your notebook.
1. What does percent natural abundance mean for an
isotope?
2. The atomic mass of germanium is 72.61 amu. Is it
likely that any individual germanium atoms have a
mass of 72.61 amu?
3. How many neutrons are in an atom of each set of
atomic number and mass numbers?
a) Z = 28, A = 59
b) Z = 92, A = 235
c) Z = 21, A = 46
d)
Z = 18, A = 42
4. Determine the number of protons and neutrons in
each isotope.
a)
33
P
b) 40 K
c) 222 Rn
d) 99 Tc
4. Silicon has three naturally occurring isotopes: Si-28 with mass 27.9769 amu and a natural abundance of
92.21%, Si-29 with mass 28.9765 amu and a natural abundance of 4.69%, and Si-30 with mass 29.9737 amu
and a natural abundance of 3.10%. Calculate the atomic mass of silicon.