Download Name________________________________ Period_________

Name: _____________________________ Period: _____ Date: __________________________
Interviewing Atomic Theorists
Democritus
1. Democritus’ ideas about atoms included five major points.
a. All matter is made up of __________________________
particles called __________________________.
b. There is a void, made of __________________________
between atoms.
c. Atoms are completely __________________________.
d. Atoms are, ___________________________ with no
internal structure.
e. Atoms vary in
i. __________________________
ii. __________________________
iii. __________________________
John Dalton
2. What is John Dalton known as the father of?
3. John Dalton wrote a book called “A New System of
Chemical Philosophy.” What did this book include?
4. How did Dalton think that atoms should be identified?
5. Dalton’s atomic theory includes five basic ideas.
a.
b.
c.
d.
Chemical elements are made of __________________________
The atoms of an element are identical in their __________________________
Atoms of different elements have different __________________________
Atoms only combine in small, whole number ratios such as 1:1, 1:2, 2:3
and so on.
e. Atoms can be neither __________________________ or
__________________________.
J.J. Thomson
6. What subatomic particle did
Thomson discover?
7. Where did Thomson think that
these particles came from?
8. What charge did these particles
have?
9. How tiny were these particles
compared to hydrogen atoms?
10.
Where did Thomson think these particles were located in an atom?
Earnest Rutherford
11.
Rutherford did an
experiment where he shot
heavy particles at very thin
piece of gold foil. What did
he expect to happen?
12.
What actually happened in the experiment?
13.
What did Rutherford conclude about the structure of the atom?
Niels Bohr
14.
Bohr suggested that
__________________________ orbit the nucleus in
different energy levels.
15.
Electrons farther from the nucleus have
_____________ energy, and will give off that energy
as light when the move back towards the
nucleus.
16.
Why is Bohr’s model of an atom sometimes called the “planetary model”?
Quantum Theorists
17.
What is not known about the locations of
electrons?
18.
What is known about the locations of
electrons?
19.
What is the region called around the nucleus
where electrons are most likely to be?
20.
There are different orbitals
maximum they can hold.
a. _________________ can hold
b. _________________ can hold
c. _________________ can hold
d. _________________ can hold
name them and how many electrons
____________
____________
____________
____________
electrons
electrons
electrons
electrons
maximum
maximum
maximum
maximum
Con
clusion Questions
1. Look at the five points of Democritus’ atomic theory. Which do you think still
hold true today? Don’t just put the letters, but summarize the points.
2. Look at the five points of Dalton’s atomic theory. Which do you think still hold
true today? Don’t just put the letters, but summarize the points.
3. Based on what you know, whose finding do you think has made the most
significant impact on the development of atomic theory?