atoms and elements
an atom is made up of a nucleus and outer shells, within the nucleus, protons and neutronw exist, protons have a realtive mass of +1, they are possitively charged, neutrons have a relative mass of 0, they have no charge, the nucleus is where the mass of an atom i. the elctrons in the outer shell have relatively no as and are negatively charged, chemical reactions take place n te outer shells of atoms. this is because, it is where gravity of the nucleus has least effect and therefore takes less energy. an atom always has an overall chrage of zero, therefore, the numbers of protons and electrons must be the same, this number is the atomic number.
an element is, a substance which contains only one type of
atoms want to gain the stable electron configuration of a noble gas, which has a full outer shell, therefore, they react in order to lose gain or share electrons to acheive this.