All chemical elements are amde up of atoms. atoms have: a small nuetron made up of protons and nuetrons , electrons surrounding the nucleus.
All atoms of the same element have the same number of protons and electronsin each o ftheir atoms.
Proton- has a positive charge
Nuetron-has a negative charge
Electron- has a negative charge.
An atom has has the same number of protons and nuetrons so the whole atom is nuetral. The atomic number of an element is the number of protons and electrons it has got.
Molecules are formed when two or more atoms are joined together.
Diatomic molecules are made up of only two atoms, for example the oxygen molecule has the formula O2 .