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Hnr Chem Chpt 3 Test
| Term | Definition |
|---|---|
| Chemical Reaction | The transformation of a substance or substances into one or more new substances. |
| Law of Conservation of Mass | Which states that mass is neither created nor destroyed during ordinary chemical reactions or physical changes. |
| Law of Definite Proportions | A chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound. |
| Law of Multiple Proportions | If two or more different compounds are composed of the same two elements, then the ration of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers. |
| Atom | as the smallest particle of an element that retains the chemical properties of that element. |
| Nuclear Forces | These short-range proton-neutron, proton-proton, and neutron-neutron forces hold the nucleus particles together. |
| Atomic Number | Number of protons of each atom of that element. |
| Isotopes | Different # of neutrons |
| Mass Number | The total number of protons and neutrons that make up the nucleus of an isotope. |
| Hyphen Notation | Name of Element - Mass of a Number |
| Nuclear Symbol | Superscript = mass number & Subscript = atomic number |
| Nuclide | A general term for a specific isotope of an element. |
| Atomic Mass Unit | Exactly 1/12 the mass of a carbon-12 atom. |
| Average Atomic Mass | The weighted average of the atomic masses of the naturally occurring isotopes of an element. |
| Mole | Amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon-12 |
| Avogadro's number | 6.022 * 10^(23) -- the number of particles in exactly one mole of pure substance. |
| Molar Mass | The mass of one mole of a pure substance. |