Unit 2 Atoms Review KEY
1. What scientist developed a model of an atom and said the electrons travel in a specific orbital
shell? Niels Bohr
2. What scientist developed a model of an atom that showed electrons traveling in an electron
cloud? Erwin Shrodinger
3. What are the three subatomic particles? Proton, Neutron, Electron
4. Protons – have a postive charge
5. Atomic Number=# of Protons = # of Electrons
6. Neutrons – have a NEUTRal charge
7. Protons and Neutrons are found in the nucleus.
8. Which two parts of the atom have a amu of 1? Protons and Neutrons
9. Which part of the atom has an amu of almost zero? Electrons
10.
Which two subatomic particles have the most mass? Protons and Neutrons
11.
What is NOT found in the nucleus? Electrons
12.
The Atomic Mass = protons + neutrons
13.
Electrons – have a negative charge
14.
Electrons orbit the nucleus in electron shell OR energy levels.
15.
What determines the identity of the element? Number of Protons
16.
CIRCLE the atom to the right
has the MOST mass?
17.
An atom consists mostly of
empty space. (Think of the area outside the nucleus)
18.
Can two atoms have the same atomic mass but different number of neutrons and
electrons? True or False (circle one) *It is the protons that determine the identity of the
element
19.
Valence electrons are the electrons on the outer most energy level.
20.
How many valence electrons does the atom to the right have? 1
21.
For an atom to be neutral, it must have the same number of
protons (+) and electrons (-). *Protons and electrons must be equal
in a stable atom.
22.
Which two subatomic particles are used to find the charge of the
atom?
protons and electrons
23.
What two subatomic particles are used to find the atomic mass of an atom?
protons and neutrons
24.
Protons, Electrons, and Neutrons are all subatomic particles.
25.
Fill in the following information
Atom Name
Atomic #
Electrons
Protons
Neutrons
Atomic Mass
Hydrogen
1
1
1
(1-1) 0
1.008
Lithium
3
3
3
(7-3) 4
6.941
Sodium
11
11
11
(23-11) 12
22.990
Potassium
19
19
19
(39-19) 20
39.098
Rubidium
37
37
37
(85-37) 48
85.468
Cesium
55
55
55
(133-55) 78 132.905
Francium
87
87
87
(223-87) 136 223
Use the chart above to answer the following questions:
26. As the atomic mass increases the atomic number increases.
27. Does the atomic mass or atomic number increase at a higher rate? the atomic mass increases at a
higher rate than the atomic number
28. As the protons increase the neutrons increase.