Atomic Theory, Atomic Theory

Ion

A charged atom

Anion

A negatively charged ion

Cation

A positively charged ion

Description of Rutherford's model

A small positive core with small negative particles circling it. Like our solar system.

Description of Thomson's Model

A sphere that is positive with small negative particles mixed within it. Like pudding

Metal

An element that is a good conductor of heat and electricity

Non-Metal

An element that is a poor conductor of heat and electricity

Isotopes

Atoms of the same element that have different numbers of neutrons

Democritus

Greek philosopher that first proposed the idea of a "atomos". That was the word for a mass that cannot be divided further. This is where the term "atom" originates.

Aristotle

Greek philosopher that thought there are 4 elements (air, fire, water, and earth)

Neutron

Non charged particle

atomic mass

Number of isotopes

Mass number

Number of protons and neutrons

Scientist that discovered the nucleus

Rutherford

Gold Foil

Rutherford did this experiment using alpha particles. Deflected electrons proved there was a small positively charged nucleus.

James Chadwick

Scientist who discovered the neutron

Niels Bohr

Showed that electrons move about the nucleus only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitted.

Atom

Smallest particle of an element

Scientist that discovered electrons.

Thompson

Description of Dalton's Model

a small sphere that is the most basic thing; cannot be broken down

Metalloid

an element that has properties of both metals and nonmetals

Electron

negatively charged particle

Atomic number

number of protons

Proton

positively charged particle

valance electrons

the number of electrons in the outermost energy level