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22 Cards in this Set
- Front
- Back
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LAW OF CONSERVATION OF MASS
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mass is neither created nor destroyed during ordinary chemical reactions or physical changes
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LAW OF DEFINITE PROPORTIONS
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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
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LAW OF MULTIPLE PROPORTIONS
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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
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DALTON'S ATOMIC THEORY
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-All matter is composed of extremely small particles called atoms
-Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties -Atoms cannot be subdivided, created, or destroyed -Atoms of different elements combine in simple whole-number ratios to form chemical compounds -In chemical reactions, atoms are combined, separated, or rearranged |
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MODERN ATOMIC THEORY
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-Atoms are divisible into even smaller particles
-A given element can have atoms with different masses -All matter is composed of atoms -Atoms of any one element differ in properties from atoms of another element. |
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PROTONS
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positively charged particle
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NEUTRONS
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neutral particles
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ELECTRONS
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negatively charged particles
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ATOMIC MASS UNIT (AMU)
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exactly 1/12 the mass of a carbon-12 atom
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JJ THOMSON
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his cathode-ray tube experiments measured the charge-to-mass ratio of an electron
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ERNEST RUTHERFORD
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his gold foil experiment led to the discovery of a very densely packed bundle of matter with a positive electric charge which he called the nucleus (worked with Marsden and Geiger)
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JAMES CHADWICK
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discovered neutrons
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NUCLEAR MODEL OF THE ATOM
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protons were at the center of the atom and the electrons orbited the nucleus (Niels Bohr stated that electrons traveled in a specific pattern)
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NUCLIDE
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a general term for a specific isotope of an element
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ATOMIC NUMBER
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the number of protons of each atom of that element
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MASS NUMBER
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the total number of protons and neutrons that make up the nucleus of an isotope
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ISOTOPES
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atoms of the same element that have different masses
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IONS
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an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge
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AVERAGE ATOMIC MASS
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the weighted average of the atomic masses of the naturally occurring isotopes of an element
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MOLE
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amount of a substance that contains as many particles as there are atoms in exactly 12 g of carbon-12
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AVOGADRO'S NUMBER
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the number of particles in exactly one mole of a pure substance (6.0221415 x 10^23)
^round to 6.02 |
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MOLAR MASS (GRAM FORMULA MASS)
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the mass of one mole of a pure substance
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