Unit 4 - Atomic Structure

Front

What are atoms?

Back

Atoms are the smallest indivisible particles that make up all matter.

Front

Who proposed that all matter is composed of atoms?

Back

Democritus proposed that all matter is composed of small indivisible particles called atoms.

Front

What is the Gold Foil Experiment?

Back

The Gold Foil Experiment was an experiment conducted by Rutherford that demonstrated that atoms have a small, dense nucleus.

Front

What were the results of the Gold Foil Experiment?

Back

Some particles bounced back, but most passed through the foil.

Front

What is the Plum Pudding Model?

Back

The Plum Pudding Model, proposed by Thomson, suggests that atoms are positively charged spheres with negatively charged electrons embedded throughout.

Front

What is an ion?

Back

An ion is a charged atom, which can be either positively or negatively charged.

Front

What is average atomic mass?

Back

Average atomic mass is the weighted average of all naturally occurring isotopes of a given element.

Front

What is the atomic number?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the atomic mass number?

Back

The atomic mass number is the total number of protons and neutrons in an atom's nucleus.

Front

Who proposed the atomic theory that matter is made of atoms?

Back

John Dalton proposed the atomic theory that matter is made of atoms.