proton

Everyday

(science) A tiny particle with a positive electric charge, found in the nucleus (centre) of every atom. tree →

In the lessons

In science lessons about atoms, an atom has protons and neutrons in the nucleus and electrons around it. The number of protons decides which element it is: hydrogen has 1, carbon has 6, oxygen has 8, gold has 79. Phrases: «protons, neutrons and electrons», «proton number», «atomic number».

Examples

• A hydrogen atom has just one proton. tree →
• Protons have a positive charge. tree →
• The number of protons tells you which element it is. tree →
• Carbon has six protons in its nucleus. tree →
• Protons and neutrons are in the nucleus. tree →
• Scientists smash protons together in the Large Hadron Collider. tree →

Note

Countable. Charges: proton +, electron −, neutron 0. Maths in science: atomic number = number of protons; in a neutral atom, protons = electrons. Protons are much heavier than electrons (about 1836 times).