Name: _______________________________________ #: _____ Class: _____ Date: ____________________
QUIZ #6 – Isotopes EXTRA ASSIGNMENT
1. Here are three isotopes of an element:
12
C
6
13
C
6
14
C
6
a. The element is: __________________
b. The number 6 refers to the _________________________
c. The numbers 12, 13, and 14 refer to the ________________________
d. How many neutrons are in the first isotope? _____________________
e. How many neutrons are in the second isotope? __________________
f.
How many neutrons are in the third isotope? ____________________
2. Complete the chart, then determine if it is the most common isotope – mark yes or no in the last column:
Most
# of
# of
# of
Isotope name atomic #
mass #
common?
protons
neutrons
electrons
potassium-37
oxygen-16
uranium-235
3. Write the most common isotope in hyphen notation for the following elements. The most common isotope
can be found by rounding the atomic mass found on the periodic table to the nearest whole number.
a. Na:
c. Al:
b. As:
d. Rn:
4. Write the most common isotope in nuclear notation for the following elements.
a. Fluorine:
c. Zinc:
b. Iodine:
d. Hydrogen:
5. Determine the average atomic mass for the following. SHOW YOUR WORK! BE THOROUGH!
a. Naturally occurring europium (Eu) consists of two isotopes. Europium-151 has an abundance of
48.03% and Europium-153 has an abundance of 51.97%. What is the average atomic mass of
europium?
b. Strontium consists of four isotopes: Strontium-84 (abundance of 0.50%), Strontium-86 (9.9%),
Strontium-87 (7.0%), and Strontium-88 (82.6%). Calculate the average atomic mass of strontium.
c. The natural abundance for boron isotopes is 19.9%
atomic mass.
10
B and 80.1%
11
B. Calculate boron’s average