Unit 3 Review

This scientist discovered the center of the atom was very small, dense and positivity charged

• Rutherford

• Thompson

• Bohr

• Democritus

The subatomic particle with a positive charge is

• The proton

• The neutron

• The electron

• The cork

What is equal to the number of protons plus the number of neutrons?

• Mass number

• Atomic number

• Average atomic mass

• Electron number

When an atom gains electrons it has

• A negative charge

• A positive charge

The atomic number of an atom tells us how many ____ it has

• Protons

• Electrons

• Neutrons

• Corks

What is found in an atom's nucleus

• Protons and Neutrons

• Electrons and Protons

• Neutrons and Electrons

• Only protons

What equipment did Thomson use to study the atom

• Cathode ray tube

• Gold foil and alpha particles

An atoms gets a positive charge by

• Loosing electrons

• Gaining Electrons

• Gaining Protons

An anion has a _______ charge.

• Negative

• Positive

• Neutral

_______ are atoms that have the same atomic number by different mass numbers.

• Isotopes

• Cations

• Elements

• Anions