Worksheet: Development of Atomic Theory Name___________________
True-False:
place a "+" in the blank if the statement is true, and a "O" in the blank
if the statement is false.
1. Dalton's atomic theory stated:
a. atoms are indivisible. _____
b. all atoms of the same element are alike. _____
c. atoms unite in small, whole number ratios _____
to form compounds.
2. The Greek philosopher Democritus was one of the first _____
to suggest the existence of atoms.
3. The word "atom" means invisible. _____
4. A theory is an explanation of observable facts and _____
phenomena.
5. Aristotle supported the idea of the atom. _____
6. From the "gold-foil" experiment it was concluded that _____
the atom is mostly empty space.
Short Answer and Fill in the Blanks:
1. What must models and theories do in order to remain valid?
a.
b.
2. The "gold-foil" experiment had the following results: ____________ of the
alpha particles were deflected, ______________ of the alpha particles
were reflected, and _____________ of the alpha particles passed through
the gold foil.
