Name: ____________________________
Date: _______ Block: _____________
1.
Complete the table below for the isotopes given.
MAKE SURE YOU REPLACE THE “?” marks with the appropriate symbol or number!
Symbol Name Mass
Number
Number of
Protons
Number of
Neutrons
Number of
Electrons
13
?
?
O 2-
75
?
As
48
20
2+
2-3, Find the average atomic weight of the following elements, given their isotopes and their percent abundances. The superscript number is the mass and the number in parenthesis is the relative abundance.
SHOW YOUR WORK! – write out the equation you are using for EACH problem
2.
Silicon - 28 (92.2%), Silicon - 29 (4.7%), Silicon - 30 (3.1%)
3.
Magnesium – 24 (78.70%), Magnesium – 25 (10.13%), Magnesium – 26 (11.17%)
4.
If the average atomic mass of chlorine is 35.453, which isotope is most abundant
Chlorine-35 or Chlorine-37? ________ How do you know?

5.
Write the nuclear symbol for Chlorine – 37.
6.
Write the nuclear symbol for Chlorine-35.
7.
Write the nuclear symbol for Sodium-24.
8.
In the blank below indicate where each statement is true or false. For each FALSE
statement, identify the incorrect part and MAKE it TRUE!
A.
_______ An element that has an atomic number of 29 indicates that the atom always has 29 protons, 29 neutrons and 29 electrons.
B.
_______ An atom of the isotope 60 Fe has 34 neutrons.
C.
_______ An atom of 31 P contains 15 protons, 16 neutrons and 31 electrons.
D.
_______
E.
_______
23 Na and 24 Na are isotopes.
24 Na has one more electron than 23 Na.
9.
How many neutrons are in each of the following isotopes?
A.
Titanium – 46
B.
Plutonium – 242
__________
__________
C.
Uranium – 235 __________
D.
Tungsten – 186 __________
10.
An atom of an element has an atomic number of 24 and a mass number of 52. What are the isotopic notation, the name and the number of protons, neutrons and electrons in the atom?
A.
Nuclear symbol
B.
Name of element _________________
C.
# of protons ______ # of neutrons ______ # of electrons ______