Name
Period:
What determines the element of an atom?
In shorthand, write out these isotopes.
1.Potassium-40
2. Sulfur-34
3. Carbon-14
Element Lakesium has 2 different isotopes: Lakesium-56 (98% abundance) and Lakesium-57 (2%
abundance. What is the average atomic mass of Lakesium?
Element Lancerium has three different isotopes. The first has an atomic weight of 15.6 amu at 89%
abundance, the second has a weight of 16.2 amu at 6% abundance, and a third which has a weight of
17.0 amu at 5% abundance. What is the average atomic mass of Lancerium?
Gamma rays are very harmful to humans, yet alpha particles are not as harmful as long as they are not
ingested. Why is that?
What atom is formed when polonium-210 decays
by losing an alpha-particle? Write the nuclear
equation.
Nitrogen-14 is formed through a beta-decay
reaction. What are the reactants in this equation?
During alpha and beta decay (nuclear reactions), the element of the atom changes. Why is that?
Name
Period:
In order of development, describe both Bohr and Rutherford’s models of the atom and why they were
different.
What is a quantum?
How many electrons are in these sublevels?
1. 1s
2. 5p
3. 4p
4. 4f
How many electrons do these atoms have?
1. Be
2. Au
3. Ne
For each atom, write the electron configuration.
1.
2.
3.
How many sublevels does energy level 3 have? How many electrons can fit in energy level 3?
Name and describe the three main rules for electron configuration.
1.
2.
3.
Ms. Ramos is having a bad day and can’t seem to get her electron configurations correct.  What is
wrong with each electron configuration and which rule does it violate?
1. 1s23d102p32s1
2. 1s12s12p3
3. 1s22s142p6
Please draw and fill out an electron configuration for Arsenic. Write out the electron configuration using
SHORTHAND (noble gases).