Atoms, Elements, Periodic Table Test 2025

Front

What is an atom?

Back

The smallest unit of an element, consisting of protons, neutrons, and electrons.

Front

What is an element?

Back

A pure substance that cannot be broken down into simpler substances by chemical means, made up of atoms with the same number of protons.

Front

What is the periodic table?

Back

A tabular arrangement of elements organized by increasing atomic number, showing periodic trends.

Front

What are protons?

Back

Positively charged subatomic particles found in the nucleus of an atom.

Front

What are neutrons?

Back

Neutral subatomic particles found in the nucleus of an atom, with no charge.

Front

What are electrons?

Back

Negatively charged subatomic particles that orbit the nucleus of an atom.

Front

What is atomic number?

Back

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

Front

What is mass number?

Back

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

Front

What are valence electrons?

Back

Electrons in the outermost energy level of an atom that are involved in chemical bonding.

Front

What happens when an atom gains electrons?

Back

It becomes negatively charged.