Unit 3: Atomic Theory & the Mole
Unit Review Worksheet
Name: ______________________________
Date: ________________ Class: _________
1. What idea did Democritus have that went against the ideas of the time?
2. What are the premises of Dalton’s Atomic Theory?
3. What did JJ Thompson discover in the late 1880’s while playing with a cathode ray tube? What was this
discovery proof of?
4. Explain the plum pudding model. What do each of the parts represent?
5. What surprised Ernest Rutherford during his gold foil experiment? What was this evidence of?
6. Draw an example of the planetary model of atoms and tell who invented it.
7. How did Rutherford and Chadwick discover the neutron?
8. Fill in the blanks in the following table.
Name
Mass
Charge
Location
9. Define isotope.
10. Fill in the blanks in the following table.
Chemical
Mass Number
Atomic
Symbol
Number
Cd
114
Number of
Protons
Number of
Neutrons
Number of
Electrons
25
I
31
72
11. Write the following in isotopic notation:
a. U-238
b. F-19
c. C-13
12. Find the atomic mass of a sample of nitrogen atoms. Assume that 43.7% of the mixture is N-14 and
57.3% of the mixture is N-13.
13. How many particle are in 1 mole?
14. How many atoms are in 1 mole?
15. How many molecules are in 1 mole?
16. How many ducks are in 1 mole?
17. What is the molar mass of As?
18. How many moles are in 36.4 grams of Kr?
19. How many grams are in 5.56 moles of Be?
20. How many atoms are in 23.33 grams of Nickel?
21. How many atoms are in 4.6 moles of SrO?
22. How many grams are in 27 atoms of AlN?
23. How many moles are in 95.67 grams of Li2S?
24. What is the molar mass of NH4NO3?
25. How many grams are in 2.00 moles of Cobalt?