CHMI-1041EL Lecture Notes - Lecture 3: Unified Atomic Mass Unit, Periodic Trends, Thermal Conductivity
18 Oct 2016
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1839: all protons and neutrons are located inside the nucleus, very small in comparison to an atom, de(cid:374)se; accou(cid:374)ts for al(cid:373)ost all of the ato(cid:373)"s (cid:373)ass. Nucleon: made up of all the particles found in the nucleus, consists of protons and neutrons. Charge neutrality: the number of protons equals the number of electrons; creating a charge of zero. Atomic number: the number of protons in the nucleus of an atom; also represents the number of electrons (z is used as a general designation of an atomic number). Mass number: the sum of the number of protons and the number of neutrons in the nucleus of an atom (a is used as a general designation of a mass number). Element: a pure substance where all atoms have the same atomic number. In nature, most elements contain mixtures of isotopes. Atomic mass: the calculated average mass for the isotopes of an element, expressed on a scale where.
