PPT Slide
- We canít measure atomís masses directly, only relatively.
- Dalton assigned an atomic mass of 1 to hydrogen, the lightest known substance.
- Relative mass of atoms of other element in a hydrogen compound from ratio of its mass to that of hydrogen.
- Lavoisier showed that water contains 8 g O for every 1 g H, so Dalton assigned a relative atomic mass of 8 to O.
- He assumed that there are the same number of oxygen atoms in 8 g oxygen as hydrogen atoms in 1 g hydrogen.
- True only if a water molecule consists of one oxygen atom for every hydrogen atom (symbolized HO).
Notes: