Isotopes
1. What is an isotope?
2. How is an isotope formed?
3. What does the number next to isotopes signify?
4. How can you tell isotopes apart?
5. How can you tell if two substances are isotopes of each other?
6. Three isotopes of an element:
a. The element is: ___________________________
b. The number 6 refers to the _____________________________
c. The numbers 12, 13, and 14 refer to the __________________________________
d. How many protons and neutrons are in the first isotope? _______________________________
e. How many protons and neutrons are in the second isotope? _____________________________
f. How many protons and neutrons are in the third isotope? _______________________________
7. Which of the following are sets of isotopes?
12
C, 13C, 14C
12
C, 14N, 19F
10
B, 10Be, 10Li
56
Fe, 58Fe, 59Fe
8. How do the isotopes of an element differ? How are they the same?
Differ:
Same:
9. Which element contains the largest number of neutrons per atom?
a. Bismuth-210
b. Polonium-210
c. Astatine-210
d. Astatine-211
10. Complete the charts:
Isotope
uranium-235
uranium-238
boron-10
boron-11
Symbol
35
17
34
16
atomic #
# of protons
mass #
# of neutrons # of electrons
Cl
Symbol
27
27
12
31
15
# of neutrons # of electrons
atomic #
17
mass #
S
83
59
# of protons
80
49
66
79
18
78
atomic #
mass #
# of protons
79
190
209
115
79
# of neutrons # of electrons
Co
Mg2+
P376
92
45
21
146
92
18
9. Naturally occurring europium (Eu) consists of two isotopes was a mass of 151and 153.
Europium - 151 has an abundance of 48.03% and Europium-153 has an abundance of 51.97%.
What is the atomic mass of europium? Show all work._____________________________
rage Atomic Mass =
10. Strontium consists of four isotopes with masses of 84 {abundance 0.50%), 86 (abundance of 9.9%), 87
(abundance of 7.0%), and 88 (abundance of 82.6%). Calculate the atomic mass of strontium
Show all work ________________________
Average Atomic Mass =
11. Find the average atomic mass of Silver (Ag) if 51.83% of the silver atoms occurring in nature have
mass 106.905 g and 48.17% of the atoms have mass 108.905 g. Show all work.