Answer:
John Dalton
Explanation:
John Dalton in 1808 suggested that all matter consists of tiny particles called atoms and that the atoms of a specific element are identical.
He postulated the Dalton's atomic theory which has the following important parts;
- All matters consists of indivisible particles called atoms
- Atoms of the same element are similar and are different from atoms of other elements.
- Atoms can neither be created nor destroyed.
- Atoms combine in simple whole ratios to form compounds.
In three hours and twenty minutes from 1:40 will be 5:00
After the first 2 min the 20 g are only 10g, (1 half-life)
after other 2 more min 5g (2 half-lives)
after other 2 more min 2.5 g (3 half-lives)
after 2 more 1.25 g (4 haf lifes)