CH111 Lecture Notes - Lecture 6: Subatomic Particle, Atomic Theory, Charge Radius
Document Summary
What did early philosophers think matter was made up of: earth, air, fire, water. Greek philosopher who was the first to propose matter was not infinitely divisible; developed concept of atom. Aristotle shot down demo and set back thinking of atom by 2000 years. 5. different atoms combine in whole number ratios to form compounds. 6. in chemical reactions, atoms are separated, combined or rearranged. What was dalton wrong about: indivisibility of atoms (subatomic particles, all atoms of same element having identical properties (isotopes) Smallest particle of an element that retains the property of the element. A tool for picking up, moving, and putting down atoms. That rays were: were actually stream of charged particles, carried negative charge. Who was millikan and what is he best known for: determined charge on electron from oil drop experiment, from mass/charge ratio (previously determined by thomson), calculated electron mass, me me = 1/1840 mass of hydrogen atom.