Intro to Atoms/Organizing the Elements

Front

What is the sum of protons and neutrons in an atom called?

Back

Atomic mass or mass number.

Front

What is the negatively charged particle in an atom?

Back

Electron.

Front

How would you best describe an atom?

Back

A core (center) of protons and neutrons surrounded by electrons.

Front

Why do atomic mass units of elements have decimals?

Back

Most elements are made up of isotopes.

Front

How was the periodic table originally ordered?

Back

By increasing atomic mass.

Front

What are isotopes?

Back

Atoms of the same element that have different numbers of neutrons.

Front

What is the nucleus of an atom?

Back

The center of an atom, containing protons and neutrons.

Front

What is the charge of a proton?

Back

Positive.

Front

What is the charge of a neutron?

Back

Neutral (no charge).

Front

What is the charge of an electron?

Back

Negative.