Proton

Definition

A positively charged subatomic particle packed into the nucleus whose count fixes the identity of the element.

One proton makes hydrogen, six make carbon, eight make oxygen. Outside of stars and nuclear reactors the proton count never changes, which is why oxygen stays oxygen whether dissolved, bound in scale, or rusting steel. This permanence is what allows the periodic table to exist. Protons define the atom but do not move it.

Related concepts

Neutron · Atomic number · Atomic mass and atomic weight

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Part of The Blueprint of Water · 🧪 chemistry