The Nucleus
The positive particle
A proton
Place where electrons are found
orbitals or shells
This 5th century philosopher suggested the universe is made up of atoms but had no scientific evidence.
Democritus
This particle has a +1 or (+) charge
Protons
This is the neutral charged particle in the nucleus
Neutron
The particle with a neutral charge
A neutron
Protons and neutrons are located here
The nucleus
This scientist in the early 1800's pictured the atom as a small sphere and called it the billiard ball model.
John Dalton
This particle has a negative (-) charge
Electron
If proton and electron is the same number, the atom will be what?
Neutral
Most of the mass of the atom comes from this
The nucleus
3 types of subatomic particles
protons, neutrons and electrons
This scientist experimented with the cathode ray tube and developed the plum pudding model of the atom.
J.J. Thomson
These to particles are attracted to one another and help hold the atom together.
Protons and Electrons
When an object gains electrons (-) it develops a _______ charge
Negative
What is the charge of nucleus?
Positive
The number of protons are equal to this
electrons
This scientist shot alpha particles through a thin piece of gold foil and determined that the atom was made of mostly empty space.
Rutherford
This is how the mass of subatomic particles are measured
atomic mass units, or AMU's
In a neutral atom these are equal
Protons (+) and Electrons (-)
Who discovered nucleus?
Ernest Rutherford
The number of this particle can never change in an atom
protons
This scientist discovered that electrons could only occupy certain orbits.
Niels Bohr
These subatomic particles provide most of the mass to an atom.
Protons and Neutrons
Who opposed the theory of Democritus?
Leuccipus