Science explained

Atoms, molecules and chemical bonds

Matter is built from atoms, and chemical bonds hold atoms together in molecules and extended structures.

ChemistryAtoms

Editorial review: August 12, 2026 · Julian E. Marston

Atoms have nuclei and electrons

Protons and neutrons occupy the nucleus while electrons occupy quantum states around it.

Elements are defined by proton number

All carbon atoms have six protons; changing neutron number creates isotopes.

Bonds redistribute electrons

Covalent, ionic and metallic bonding describe different patterns of electron sharing or attraction.

Structure shapes properties

The same elements can behave differently when atoms are arranged differently.

Source trail: IUPAC: periodic table
This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.