Front

Who was one of the first people to state that matter is made up of atoms?

Back

Democritus

Front

Dalton's model of an atom is best described as

Back

a solid sphere

Front

Who provided the first evidence that atoms contain subatomic particles?

Back

Thomson

Front

Where is almost all the mass of an atom located?

Back

nucleus

Front

An electron is a particle with

Back

a negative charge, found outside the nucleus

Front

Which particle is the least massive?

Back

electron

Front

All atoms of an element have the same

Back

atomic number

Front

The number of neutrons in an atom equals the

Back

mass number minus atomic number

Front

How many electrons are there in an atom of sulfur-34?

Back

16

Front

Atoms emit energy as light when

Back

electrons move to a lower energy level