Atoms and Isotopes

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus made of protons and neutrons, surrounded by electrons.

Front

What is an isotope?

Back

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons, resulting in different mass numbers.

Front

What is atomic mass?

Back

Atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu). It reflects the mass of protons and neutrons in the nucleus.

Front

How do you determine the mass number of an atom?

Back

The mass number of an atom is determined by adding the number of protons and neutrons in its nucleus.

Front

What charge do protons have?

Back

Protons have a positive charge.

Front

What charge do neutrons have?

Back

Neutrons have no charge; they are neutral.

Front

What charge do electrons have?

Back

Electrons have a negative charge.

Front

How can you tell if two atoms are of the same element?

Back

Two atoms are of the same element if they have the same number of protons in their nuclei.

Front

What is the significance of the atomic number?

Back

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

Front

What is the mass number of Neon with 10 protons and 11 neutrons?

Back

The mass number of this Neon atom is 21 (10 protons + 11 neutrons).