atoms flashcard scms

Front

What is the atomic model that replaced Thomson's plum pudding model?

Back

Rutherford model

Front

What did Democritus believe about atoms?

Back

Atoms are indivisible and indestructible particles that make up all matter.

Front

What did J. J. Thomson conclude from his experiments?

Back

Atoms contain small negatively charged particles that are called electrons.

Front

What was a conclusion from Rutherford's gold foil experiment?

Back

The nucleus is very small and the atom is mostly empty space.

Front

What is an electron?

Back

An electron is a subatomic particle with a negative charge.

Front

What is the nucleus of an atom?

Back

The nucleus is the dense central core of an atom, containing protons and neutrons.

Front

What are protons?

Back

Protons are positively charged subatomic particles found in the nucleus of an atom.

Front

What are neutrons?

Back

Neutrons are neutral subatomic particles found in the nucleus of an atom.

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.

Front

What is the mass number?

Back

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