Build an Atom

Explore how protons, neutrons, and electrons make up atoms. Add or remove particles to create different elements and ions.

Proton (+)Neutron (0)Electron (-)HHydrogenAtomic # 1

Protons: 1

1
Determines element

Neutrons: 1

1
Affects stability

Electrons: 1

1
Determines charge

Atom Properties

Element

Hydrogen

Symbol: H

Atomic Number

1

Number of protons

Mass Number

2

Protons + Neutrons

Net Charge

0

Neutral atom

Stability

This isotope is likely stable.

Neutron to proton ratio: 1.00

Understanding Atoms

Atoms are the basic building blocks of matter. They consist of three types of subatomic particles:

  • Protons: Positively charged particles in the nucleus. The number of protons determines which element the atom is.
  • Neutrons: Neutral particles in the nucleus. They add mass and affect stability. Atoms of the same element with different numbers of neutrons are called isotopes.
  • Electrons: Negatively charged particles that orbit the nucleus in shells. They determine the atom's chemical properties and how it bonds with other atoms.

In a neutral atom, the number of protons equals the number of electrons, resulting in no net charge. If an atom gains or loses electrons, it becomes an ion:

  • Cation: An atom that has lost electrons, giving it a positive charge.
  • Anion: An atom that has gained electrons, giving it a negative charge.