John Dalton transformed Demoucritus ideas on atoms into a mordern atomic moldel.
1] all matter is made of tiny microscopic particals called atoms.
2] the atoms the same elements are identical thoes of different elements are compounds.
3] atoms of different elements combine in small, whole number ratioe to form compound.
4]chemical reactoins involve the combonations of atoms no new atoms are created [ law of simple multiple prop]