Post on 14-Apr-2017
Dalton’s Atomic Model
John Dalton• September 7, 1766 – July 27, 1844• An English chemist, physicist and
meteorologist• One of the pioneers of the development of the
modern atomic theory• Daltonism – it is the concept of Dalton’s
research about color blindness
John Dalton• In 1803, he published his first table on relative
atomic weights. He computed the atomic weights from the percentage composition of compounds
• He also contributed on Gas Laws
John Dalton’s Atomic Theory1. Elements are made of extremely small particles called
atoms.2. Atoms of a given element are identical in size, mass,
and other properties; atoms of different elements differ in size, mass, and other properties.
3. Atoms cannot be subdivided, created, or destroyed.4. Atoms of different elements combine in simple whole-
number ratios to form chemical compounds.5. In chemical reactions, atoms are combined, separated,
or rearranged.
BILLIARD BALL MODEL
Billiard Ball Model• Dalton’s atomic model• Created in 1803• Represented as a tiny indivisible uniformly dense, solid
sphere• Elements are comprised by tiny particles called “atoms”• Atoms can’t be divided, destroyed or created• Atoms of two or more elements combine to form a
compound• Has no nucleus• Become the basis for future atomic model
Billiard Ball Model• Atoms are of the same size and same
component as the element• Dalton thought that atoms are empty inside