John Dalton and His Atomic Theory
John Dalton was a British chemist who discovered the first helpful atomic theory of matter. John Dalton discovered this theory in the year 1803 (Cain, 2001). John Dalton's atomic theory states all matter is made up of atoms which are indestructible and unchangeable, elements are characterized by the mass of their atoms, compounds are formed by a combination of two or more different kinds of atoms, and atoms are not created, destroyed or converted into other kinds of atoms during chemical reactions. Many of Dalton's ideas were acquired from other chemists at the time such as Lavoisier and Higgins However, Dalton was the first to put the ideas into a universal law of atomic theory, undoubtedly his greatest achievement (Wikipedia, 2004).
According to Dalton's atomic theory all matter is made up of atoms which are indestructible and unchangeable. In other words, atoms can not be broken into smaller pieces, created, destroyed, or transformed into atoms of another element.
Also, elements are characterized by the mass of their atoms. Meaning all atoms of the same element has identical weights. Atoms of different elements have different weights.
Another statement Dalton makes in his theory is that compounds are formed by a combination of two or more different kinds of atoms (The Chemical Heritage Foundation, 2000). This suggests a practical strategy for determining relative atomic weights from elemental percentages in compounds. Experimental atomic weights could then be used to explain the fixed percentages of elements in all compounds of those elements!
Dalton's last postulate in his atomic theory is atoms of different elements have different properties. In an ordinary chemical reaction, no atom of any element disappears or is changed into an atom of another element. An example of this postulate would be; all atoms of the...