While experimenting with gases Dalton suggested that all matter is 1. made up of atoms which can't be created, destroyed, subdivided. 2. Atoms of a given element are all going to be the same. 3. Atoms of a different element are going to have different chemical and physical properties. 4. Atoms of different elements combine in simple ratio. 5. Chemical reactions may combine, separate, or rearrange but will not change,be created, or destroyed. Dalton experimented with gases when he wondered why liquids and gases could exist in the same space but solids couldn't. When he tried to explain his results he created his hypothesis for the atomic theory.