Atoms, Atomic Theory, Atomic Theory Diagram | Quizlet

TERM

neutrons

DEFINITION

subatomic particles that have a neutral or no charge

TERM

protons

DEFINITION

positively charged subatomic particles

atom

the smallest particle of an element that has all the properties of the element

TERM

orbital

DEFINITION

a space around the nucleus of an atom where an electron is likely to be found

TERM

electrons

DEFINITION

negatively charged subatomic particles

TERM

nucleus

DEFINITION

the central core of an atom; contains protons and neutrons

Modern Atomic Theory

the most recent version for the explanation and definition of an atom

Picture of Dalton's Model

Picture of Thomson's Model

Picture of Rutherford's Model

Picture of the Modern electron cloud model

Description of Dalton's Model

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

Description of Thomson's Model

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

Description of Rutherford's model

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

Cathode Ray

Experiment that showed atoms contained particles that were negatively charged.

Gold Foil

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

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.

Scientist that discovered the nucleus

Rutherford

Scientist that discovered electrons.

Thompson

atomic number

The number of protons in the nucleus of an atom

Mass number

the sum of the number of neutrons and protons in an atomic nucleus

isotope

Atoms of the same element that have different numbers of neutrons

atomic mass unit

a unit of mass that describes the mass of an atom or molecule

valence electron

Electrons on the outermost energy level of an atom