Dalton’s Atomic theory

1. Dalton’s Atomic theory Haley, Josh, Austin

2. Who was he? • John Dalton (1766-1844) developed an atomic theory that proposed that atoms were responsible for the combinations of elements found in compounds.

3. Daltons atomic theory • All matter is made up of tiny particles called atoms (true) • All atoms of a given element are identical to one another and different from atoms of other elements(false) • Atoms of two or more different elements combine to form compounds. A Particular compound is always made up of the same kinds of atoms and the same number of each kind of atom (true) • A chemical reaction involves the rearrangement, separation, or combination of atoms. Atoms are never created or destroyed during a chemical reaction. (true/false) • Atoms of different elements have different weights and different chemical properties. (true)

4. Experiments tested by Dalton • John Dalton found that things combine in different proportions over and over again. Daltons atomic theory • Dalton burnt wood and oxygen and then it turned into ashes, carbon dioxide and water vapor. The mass of wood and oxygen equal the mass of the ashes, carbon dioxide and water vapor. • One carbon atom+four hydrogen atoms- CH4

5. Where does his theory fit in the time line of history? • Dalton was the first to use the scientific method to create a theory involving atoms. • His atomic theory was proposed in 1803, hundreds of years after Aristotle first researched atoms.

6. How has his theory held up over time? • Two of his postulates have been proven wrong • These two include, All atoms of a given element are identical to one another and different from atoms of other elements & A chemical reaction involves the rearrangement, separation, or combination of atoms. Atoms are never created or destroyed during a chemical reaction • Although these two were proven false, the remaining three postulate remain accurate.