Chemistry 1.1 and 1.2 Flashcard Review

Front

What is the area around the nucleus of an atom where its electrons are most likely found?

Back

Electron cloud.

Front

What charge does an electron have?

Back

Negative.

Front

What charge does a proton have?

Back

Positive.

Front

What was one of J. J. Thomson's contributions to atomic theory?

Back

He described the atom as having a positively charged sphere with negative electrons.

Front

What are valence electrons?

Back

The number of electrons in the outermost shell.

Front

What is the nucleus of an atom?

Back

The central part of an atom that contains protons and neutrons.

Front

What is the charge of a neutron?

Back

Neutral.

Front

What is the difference between an atom and a molecule?

Back

An atom is the smallest unit of an element, while a molecule is a group of two or more atoms bonded together.

Front

What is the atomic number?

Back

The number of protons in the nucleus of an atom.

Front

What is the mass number of an atom?

Back

The total number of protons and neutrons in the nucleus.