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Chemistry Chapter 3
10/3/13
Term | Definition |
---|---|
Law of Conservation of Mass | mass is matter created nor destroyed during ordinary chemical reaction or physical change |
Law of Definite Proportions | Fact that chemical compound contains the same elements is exactly the same proportions by mass regardless of the size of sample of compound |
Law of multiple proportions | 2 or more different compounds composed of same 2 elements |
Atom | smallest particle of an element that retains the chemical properties of the element 2 regions that make up an atom |
Nuclear forces | short range proton-neutron, proton-proton, and neutron-neutron forces hold the nuclear particles together |
Atomic number (z) | element is number of protons of each atom of an element |
Isotope | atoms of same element that have different masses |
Simplest atoms | Hydrogen |
Mass number (a) | total number of protons+neutrons that make up nucleus of isotope |
Nuclide | is general term for specific isotope of an element |
Atomic Mass Unit | exact mass of carbon-12 atom |
Average Atomic Mass | Average of atom masses of naturally occurring isotopes of an element |
Mole | amount of substance that contains as many particles as there are atoms in exactly 12g of carbon-12 |
Avogadro's Number | 6.022 x 10²³ |
Molar Mass | mass of 1 mole of a pure substance |
Model of atomic theory | 1. All matter is small particles called atoms 2. Atoms of given element are identical in size, mass and properties. Atoms of different elements differ in size, mass, and properties 3. Atoms cannot be divided, created, or destroyed 4. Atoms of different |
Democritus | he called basic particle an atom |
Aristotle | thought atoms were made from the elements of the earth (wind,fire,water,earth) |
Dalton | proposed explanation for law of conservation, law of definite proportions. Said elements composed if atoms and only whole numbers of atoms can form compounds |
Thomson | proposed plum pudding model - believed negative electrons were spread evenly thru out positive charge of atom |
Rutherford | discovered volume of nucleus was very small |
Bohr | Rutherfords student who proposed model which electrons surrounded the + charge nucleus |
Shrodinger | modern atom |
Difference between continuous and discrete | continuous- continuous discrete-goes on in and desecrate is a finite number |