Structure atomique

Elements are substances with unique physical and chemical properties that cannot be broken down into other substances by chemical reactions.

Each element, like potassium, consists of atoms that differ from those of other elements.

These differences are found in the subatomic particles that make up each atom.

Two of these particle types are clustered in a central nucleus. Protons are positively charged, while neutrons are uncharged, neutral.

While both contribute to the atomic mass, each carrying approximately one atomic mass unit, the number of protons, referred to as the atomic number, defines the specific element. Changing the number of protons results in a different element.

Electrons, a third type of subatomic particle, are negatively charged and move rapidly in a cloud around the nucleus.

This cloud is mostly empty space and makes up the vast majority of an atom's volume.

Electrons remain near the nucleus because they are attracted to the positive charge of protons.

An atom contains an equal number of protons and electrons, which cancels out the positive and negative charges, leading to no net charge.

But, depending on their valence electron configuration, some atoms tend to gain or lose electrons to reach a more stable electron arrangement. In this case, they can lose electrons and become positively charged ions called cations or gain electrons and become negatively charged ions called anions.