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chemistry, atoms
Atoms, the building blocks of matter
Question | Answer |
---|---|
law of conservation of mass | mass is neither created nore 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 |
law of multiple proportions | If two or more different compounds are composed of the same two elements, then the ratio 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 | the smallest particle of an element that retains the chemical properties of that element |
atomic number | the number of protons in the nucleus of each atom of that element |
isotopes | atoms of the same element that have different masses |
nuclide | a general term for any isotope of any element |
atomic mass unit | amu, 1/2 the mass of a carbon-12 atom |
average atomic mass | weighted average of the atomic masses of the naturally occurring isotopes of an element |
mole | amount of a substance that contains as many partiles as there are atoms in exactly 12g of carbon-12 |
molar mass | mass of one mole of a pure substance |