Teacher Notes
Name
Key
Class
Date
Models of the Atom
Label each description with the correct model of the atom (Bohr, Dalton, Democritus, Rutherford,
Thomson, or quantum).
Dalton
1. Atoms of the same element are identical and are different from atoms of
other elements.
Bohr
2. Hydrogen atoms emit light when excited electrons lose packages of energy.
Thomson
3. All atoms contain tiny particles that are attracted to a positively charged
plate.
Democritus
4. I think there is a limit to the number of times that matter can be divided, but
have no data.
Rutherford
5. A very few alpha particles were deflected almost straight back by the gold
foil.
quantum
6. The probable location of electrons can be described mathematically.
7. On the back of this sheet, construct a timeline of the models of the atom. Include the names of the six
models and important discoveries that led to each. (See Changing Atomic Models Notes.)
8. Draw pictures representing the models of Thomson and Rutherford.
nucleus
+
electron (-)
Thomson
Rutherford
9. The path shown below is made by a neutron from the box passing between the charged plates. Draw
and label the path expected to be made by a proton and by an electron.
electron (-)
+
particle
source
—
proton (+)
10. Fill in the missing information in the table below.
Discovery
order
second
Relative
charge
+1
1.007276 amu*
Location in
atom
in the nucleus
electron
first
-1
0.0005486 amu
Around nucleus,
in orbitals
1
0
neutron
last (third)
0
1.008665 amu
in the nucleus
1
0
Particle
proton
Mass
*atomic mass unit
Symbols
1
1
p , p+
e , e-
n , n0