Earth Sciences 1023A/B Final: Earth Science 1023 Final Exam

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1023A/B
• Professor: Richard Secco

Document Summary

Thought to be indivisible and smallest thing that exists. John dalton in 1808 began modern theory of atom: believed all atoms were same size and weight, atoms unite to form compounds. Element single isolated group of same atom. 1897 jj thompson discovered electron is negatively charged (plum pudding model. (cid:1005)9(cid:1005)(cid:1005) e(cid:396)(cid:374)est ruthe(cid:396)fo(cid:396)d des(cid:272)(cid:396)i(cid:271)ed ato(cid:373)"s st(cid:396)u(cid:272)tu(cid:396)e (cid:894)positi(cid:448)e (cid:374)u(cid:272)leus su(cid:396)(cid:396)ou(cid:374)ded (cid:271)(cid:455) negative electrons) 1913 neils bohr used quantum theory to explain electron configuration. Atoms are composed of proton, neutron, and electron. Chemical behaviour is largely controlled by electron config: proton 1. 7x10-27 kg, neutron 1. 7x10-27 kg, electron 1. 9x10-31 kg. 118 atoms known to exist, 92 exist in nature. Properties of elements are periodic functions of their atomic number. Trends or patterns are related to atomic weight and electron config. 3 important factors for trends: left to right, electrons added to same energy level and protons added to nucleus, moving down, additional shells are added, elements gain or lose electrons to achieve full octect.