Atom Models
LT: Learn how the location and characteristics of protons, neutrons, and electrons
determine characteristics of atoms
LT: Learn how the location and characteristics of protons, neutrons, and electrons
determine characteristics of atoms
Steps for completing the worksheet:
1. Identify atomic mass from the periodic table and round to nearest whole number.
(You may use the periodic table segment on the header of this page to get your values.)
a. Example: Hydrogen (H) Atomic Mass = 1.008
b. Rounds to 1
2. Determine the number of protons and neutrons
a. The atomic number = number of protons
b. Example Hydrogen (H) = 1
c. Atomic mass = Number of Protons + Number of Neutrons
d. Example: Hydrogen (H) 1 (atomic mass) = 1 proton + 0 neutrons
e. Or…. the number of Neutrons = The Atomic Mass –The Number of Protons
f. Example: Hydrogen (H) 1 – 1= 0 neutrons
g. Put the number of protons and neutrons in the blanks
3. “Park” the electrons
a. Park from the inside out
b. Completely fill inner circles (orbits, shells) first
c. Park remaining electrons in the outer shell
4. Determine potential ion charge
a. The “parking lot” analogy
i. Ion outer shells want to be completely filled or completely empty
ii. To accomplish this electrons are either driven off an outer shell to empty or driven on the outer
shell to fill
iii. “drive” as few electrons possible
b. Example 1:
i. Sodium (Na) has 1 electron in the outer shell …7 empty parking spaces
ii. It easier to “drive” the 1 off
iii. If an (-) electron leaves the atom switches from neutral to +1
c. Example 2:
i. Oxygen has 6 electrons in the outer shell … 2 empty parking spaces
ii. It easier to “drive” 2 new electrons on
iii. If 2 (-) electrons are added the atom changes from neutral to -2
d. General rule
i. 1 electron on outer shell +1
ii. 2 electrons on outer shell +2
iii. 3 electrons on outer shell +3
iv. 4 electrons on outer shell +/-4
v. 5 electrons on outer shell -3
vi. 6 Electrons on outer shell -2
vii. 7 electrons on outer shell – 1
viii. Full outer shell – neutral
1. Identify atomic mass from the periodic table and round to nearest whole number.
(You may use the periodic table segment on the header of this page to get your values.)
a. Example: Hydrogen (H) Atomic Mass = 1.008
b. Rounds to 1
2. Determine the number of protons and neutrons
a. The atomic number = number of protons
b. Example Hydrogen (H) = 1
c. Atomic mass = Number of Protons + Number of Neutrons
d. Example: Hydrogen (H) 1 (atomic mass) = 1 proton + 0 neutrons
e. Or…. the number of Neutrons = The Atomic Mass –The Number of Protons
f. Example: Hydrogen (H) 1 – 1= 0 neutrons
g. Put the number of protons and neutrons in the blanks
3. “Park” the electrons
a. Park from the inside out
b. Completely fill inner circles (orbits, shells) first
c. Park remaining electrons in the outer shell
4. Determine potential ion charge
a. The “parking lot” analogy
i. Ion outer shells want to be completely filled or completely empty
ii. To accomplish this electrons are either driven off an outer shell to empty or driven on the outer
shell to fill
iii. “drive” as few electrons possible
b. Example 1:
i. Sodium (Na) has 1 electron in the outer shell …7 empty parking spaces
ii. It easier to “drive” the 1 off
iii. If an (-) electron leaves the atom switches from neutral to +1
c. Example 2:
i. Oxygen has 6 electrons in the outer shell … 2 empty parking spaces
ii. It easier to “drive” 2 new electrons on
iii. If 2 (-) electrons are added the atom changes from neutral to -2
d. General rule
i. 1 electron on outer shell +1
ii. 2 electrons on outer shell +2
iii. 3 electrons on outer shell +3
iv. 4 electrons on outer shell +/-4
v. 5 electrons on outer shell -3
vi. 6 Electrons on outer shell -2
vii. 7 electrons on outer shell – 1
viii. Full outer shell – neutral