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10 Cards in this Set
- Front
- Back
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what are the main subatomic particles of atoms?
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protons (+ charge), neutrons (neutral), electrons (- charge)
protons and neutrons are located in the nucleus (nucleus diameter is approx 10**-13 cm) electrons move around the nucleus, avg distance 10**-8 cm from the center |
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what is the charge for protons? electrons?
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postive charged protons: +1.602 x 10**-19 C
negative charged electrons: -1.602 x 10**-19 C |
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what is atomic number?
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the number of protons and electrons in an atom (if not equal they are ions)
chemical property of the atom is determined by the number of electrons note: the number of neutrons can vary which gives rise to isotopes |
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what is atomic mass?
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atomic mass = number of protons + number of neutrons, e.g.
13 (atomic mass) C 6 (atomic number) --> 6 protons, 6 electrons, 7 neutrons |
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what is a molecule?
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molecule: the assembly of two or more atoms
the atoms are held together by chemical bonds molecules have a molecular formula |
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molecular mass?
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the sum of the atomic mass for all atoms in a molecule
e.g. H2O; 1 + 1 + 16 amu (atomic mass units) |
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what are ions? charge?
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cation: + charged ion, formed when one or more electrons is lost
anion: - charged ion, formed when one or more electrons is added charge = atomic number - number of electrons |
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what are polyatomic ions?
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polyatomic ions are composed of several cation and anion atoms.
e.g. two Br- anions are combined with one Ca2+ cation to form CaBr2 |
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what is a structural formula?
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shows the arrangement of the atoms in a molecular formula, e.g. water:
H-O-H |
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What are acids?
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Acids generate H+ cation and an anion when dissolved in water.
e.g. H2S + H20 -> H+ + HS- |
