1. What is the atomic weight of an element if 4.00 grams of it contain 2.98 x 10^22 atoms?
A) 2.02 u B) 80.8 u C) 8.08 u D) 20.2 u E) 19.7 u
2. A hypothetical element Z has two stable isotopes:
Z-46 = 46.046 u 64.08% Z-51 = 50.826 u 35.92%
What is the average atom weight of the element?
A) 48.44 u B) 47.44 u C) 48.50 u D) 49.11 u E) 47.76 u
3. The atomic mass of 19F is 18.9984. How many isotopes of F do you expect?
A) five B) two C) one D) three E) four