| A | B |
|---|
| element | a pure substance made up of only one kind of atom |
| compound | a substance made from the atoms of two or more elements that are chemically bonded together and has a fixed ratio |
| solution | a homogeneous mixture of two or more substances in a single phase |
| homogeneous | looks like one substance; is really two |
| heterogeneous | the different parts of the mixture can be seen |
| metal | an element that is a good conductor of heat and electricity |
| nonmetal | an element that is a poor conductor of heat and electricity |
| metalloid | an element that has some characteristics of metals and nonmetals |
| chemistry | the study of composition, structure, and properties of matter and energy, and the changes they undergo |
| accuracy | how close you are to the accepted value |
| precision | the closeness a set of measurements of the same quantity made in the same way |
| Kelvin = C __ _____ | + 273 |
| Inorganic | branch of chemistry--substances not organic |
| Physical | branch of chemistry--study of changes of matter and energy |
| Analytical | branch of chemistry--identity of components/composition of materials |
| biochemistry | branch of chemistry--study of substances and processes occurring in living things |
| Theoretical | branch of chemistry--use of technology to explain observed chemistry and predict the properties of new compounds/elements |
| basic | research for the sake of acquiring knowledge |
| applied | research aimed at solving a problem |
| technological | reserach aimed at improving the quality of life |
| Rutherford | conducted gold foil experiment, discovered nucleus of atoms |
| atom | the smalles unit of an element that maintains the properties of that element |
| atomic mass unit | 1/12 the mass of a C-12 atom. |
| average atomic mass | the weighted average of the atomic masses of naturally occurring isotopes of an element |
| isotopes | atoms of the same element that have the same # of protons but different #s of neutrons |
| 1. protium 2. deuterium 3. tritium | the hydrogen isotopes |
| alpha particle | 2 protons and 2 neutrons bound together, admitted from the nucleus and has the atomic number decrease by two, the mass number decrease by 4 |
| beta particle | electron emitted from the nucleus |
| positron | particle that has the same mass as an electron but has a positive charge and can be emitted from the nucleus |
| Aufbau | electrons occupy lowest energy level first |
| Pauli | electrons in the same atom have different set of quantum numbers |
| Hund | every orbitas in the same energy level gets one electron before any has 2 |
| law of conservation of mass | mass cannot be created/destroyed, but can be rearranged (Lavoiser) |
| law of constant composition/definite proportions | a chemical compound always contains exactly the same proportion of elements by mass (Proust) |
| Law of multiple proportions | Dalton's law, said that elements combined in fixed ratios/whole numbers |
