Name__________________________

1. All atoms are composed of three fundamental particles, ______________, ______________, and ________________.

2. The proton is _________times as massive as an electron.

3. What is meant by atomic number?

4. Defien the term isotope.

5. Give the name of the three isotopes of hydrogen, and the mass number of each.

6. Give the number of neutrons in each of the following nuclides:

_____O-16 ____O-17 ____C-12 ____C-14 ____Cl-35 ____Cl-37

____U-235 ...____ K⁺ - 40 .... _______Se^-2 - 79

7. The mass of all elements are measured relative to a ___________nuclide.

_____8. If 25 % of chlorine atoms are Cl-37 and 75 % are Cl-35, determine the average mass. SHOW YOUR WORK.

____9. Determine the average mass of a chromium atom SHOW YOUR WORK..

2.38% Cr-54; 9.55% Cr-53; 83.8% Cr-52; 4.31% Cr-50

10. What can you say about the amount of U-238 that occurs in nature vs the amount of U-235 if these are the two most important naturally occuring isotopes of uranium?

The symbol A stands for the unit Angstrom where 1 A = 10^-10m

_______11. Convert 4 A to m.

_______12. Convert 6380 A to nm.

_______13. How many C-atoms with diameter 1.54 A will fit side by side in a space of 1 cm?

______14. About ? (what part) of the volume of an atom is occupied by the nucleus of the atom?

15. How does the mass of a neutron compare to that of a proton?

16. State the main concepts of Daltons Atomic theory.

17. Describe Rutherford's Gold foil experiment and and state the theory he proposed.

18. How did J.J. Thompson advance the atomic.