1.
Antoine Lavoisier: French chemist known as the father of modern chemistry
2.
Atomic mass unit (amu): A unit used to measure the mass of particles in atoms; a proton or neutron has a mass of 1 amu.
3.
Atomic number (Z): the number of protons in the nucleus of an atom
4.
Atomos: greek word for atom- means not able to be divided
5.
Average atomic mass: weighted average of the atomic masses for the isotopes of an element
6.
Avogadro's number: The number of representative particles of a substance present in 1 mole of that substance
7.
Cathode-ray tube: evacuated glass tube in which a stream of electrons emitted by a cathode strikes a fluorescent material, causing it to glow
8.
Dalton's Atomic Theory: 1) elements are composed of atoms. 2) atoms of same element are identical, but differ from other elements. 3) elements can mix together 4) atoms only change when mixed with other elements
9.
Democritus: Greek philosopher who developed an atomistic theory of matter (460-370 BC)
10.
Deuterium: an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)
11.
Electrons: negatively charged particles found outside the nucleus
12.
Isotope: one of two or more atoms with the same atomic number but with different numbers of neutrons
13.
J J Thomson: 1897 used cathode ray and positively charged plates to discover electrons (thought electrons were "stuck" in uniform, positively charged matter to form an atom)
14.
James Chadwick: Discovered the neutron
15.
Law of conservation of mass: a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system
16.
Law of definite proportions: (chemistry) law stating that every pure substance always contains the same elements combined in the same proportions by weight
17.
Law of multiple proportions: (chemistry) law stating that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation
18.
Mass number (A): the sum of the number of protons and neutrons in the nucelus of an atom
19.
Molar mass: the mass in grams of 1 mol of a substance
20.
Mole: the SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in exactly 12 g of carbon-12
21.
Neutron: an elementary particle with no charge and mass about equal to a proton
22.
Nuclear Model of the atom: created by Ernest Rutherford. Replaced the Plum Pudding Model. Atom is like a miniature solar system with the positive particles in the middle and the negative particles orbiting as the planets do around the center.
23.
Nucleus: the positively charged dense center of an atom
24.
Picometer: a metric unit of length equal to one trillionth of a meter
25.
Plum Pudding Model of the atom: atoms are balls of positively charged material with negative electrons scattered throughout
26.
Protium: the simplest form of hydrogen that contains 1 proton and no neutrons in the nucleus; the nucleus is surrounded by 1 electron
27.
Proton: a stable particle with positive charge equal to the negative charge of an electron
28.
Qualitative Analysis: the act of decomposing a substance into its constituent elements
29.
Quantitative Analysis: chemical analysis to determine the amounts of each element in the substance
30.
Relative atomic mass: (chemistry) the ratio of the atomic mass of an element to half the atomic mass of carbon-12
31.
Scanning Tunneling Microscope (STM): microscope that measures electrons that leak or "tunnel" from the surface of the specimen
32.
Strong nuclear force: a powerful force of attraction that acts only on the neutrons and protons in the nucleus, holding them together
33.
Tritium: a radioactive isotope of hydrogen
