4.1

Question 1

the smallest unit of an element that maintains the properties of that element

Answer 1

atom

Question 2

a subatomic particle that has a negative charge

Answer 2

electron

Question 3

in physical science,an atom’s central region, which is made up of protons and neutrons

Answer 3

nucleus

Question 4

a region around the nucleus of an atom where electrons are likely to be found

Answer 4

electron cloud

Question 5

He though that matter is composed of atoms. He also believed that you would never end up with a particle that could not be cut.

Answer 5

Democritus

Question 6

He believed you would never end up with a particle that could not be cut.

Answer 6

Aristotle

Question 7

He though all substances are made of atoms. Atoms are particles that cannot be created, divided, or destroyed

Answer 7

Dalton

Question 8

He discovered that there are small particles inside the atom. This mean atoms can be divided into smaller parts. He invented a cathode-ray tube

Answer 8

Thompson

Question 9

He decided to test Thompson’s theory. He designed an experiment to study the parts of the atom. He aimed a beam of small, positively charged particles at a thin sheet of gold foil. He put a special coating behind the foil. The coating glowed when it was hit by the positively charged particles. He could see where the particles went after hitting the foil.

Answer 9

Rutherford

Question 10

disproved Bohr’s theory and present day experiments prove that electrons move randomly in space within the atom known as

Answer 10

Shrodinger and Heisenberg