Dalton’s Atomic Theory BY: Ali, Steph, Hunter, Victoria

Who is John Dalton? English Teacher Chemist in the early 1800’s Identified the hereditary nature of red-green color blindness Revealed concept of Partial Pressures Credited as the father of modern atomic theory

What are the 5 key points of his theory? 1. 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.

Experiments Dalton used symbols to represent the elements. He imagined atoms to be tiny spheres, thus to draw atoms would be to draw circles. He used patterns within the circles to distinguish the different elements.

Theory in science timeline Created in 1803 Dalton created his theory near the beginning of the science timeline Allowing other scientist to build on Daltons theory.

How did it hold? Many other chemists built off of his theory His theory is pretty close to what we know about atoms today. We know that atoms are small particles, they can’t be created or destroyed, they have chemical reactions, and they form chemical compounds. Dalton was the one who has discovered this.