Honors Chemistry
Worksheet 2-1
Name_________________________
Atomic Structure
Period_______
1. Which statements in Dalton’s atomic theory are now considered to be incorrect? Describe
how the modern atomic theory differs from these statements.
2. Which subatomic particles are charged?
3. Describe the structure of a typical atom. Identify where each subatomic particle is located.
4. Compare and contrast Thomson’s plum pudding atomic model with Rutherford’s nuclear
atomic model.
5. What caused the deflection of the alpha particles in Rutherford’s gold foil experiment?
6. Which statement is consistent with the results of Rutherford’s gold foil experiment?
a. All atoms have a positive charge.
b. Atoms are mostly empty space.
c. The nucleus of an atom contains protons and electrons.
d. Mass is spread uniformly throughout an atom.
7. Which subatomic particle was discovered by researchers working with a cathode ray tube?
8. Which subatomic particle identifies an atom as that of a particular element? How is this
particle related to the atom’s atomic number?
9. Which subatomic particles account for most of an atom’s mass?
10. Complete the table for the following elements.
Element # of protons # of electrons
# of neutrons Atomic # Mass #
Manganese 25 30
Sodium 11 12
Bromine 35 45
Yttrium 39 89
Arsenic 33 75
Actinium 227
