The nucleus is in the middle of the atom, it comtains protons and neutrons.
Protons are positively charged. Neutrons have no charge (they're neutral). So the nucleus has a positive charge overall because of the protons.
The electrons move around the nucleus. They are negatively charged.
The number of protons equals the number of electrons.
Atoms have no charge overall. They are neutral. The charge on the electrons is the same size as the charge on the protons - but opposite. This means that the number of protons always equals the number of electrons in an atom. If some electrons are added or removed, the atom becomes charged and then is an ion.
Elements consist of one type of atom only.
Atoms have different number of protons, neutrons and electrons. It's the number of protons in the nucleus that decided what type if atom it is. E.g. An atom with one proton in it's nucleus is hydrogen and an atom with two protons is helium. If a substance contains only one type of atom, it's called an element.
Comments
No comments have yet been made