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59 Cards in this Set
- Front
- Back
Avogadro's constant is: |
6.02x10^23 - the number of particles in 1 mole of a substance |
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Relative atomic mass:
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The number of times heavier a given atom is than one twelfth of an atom of carbon 12
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Relative formula mass:
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Sum of the relative atomic masses of constituent atoms.
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The empirical formula is:
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The simplest ratio of atoms of each element in a compound.
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The molecular formula is:
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The numbers and types of atoms in a molecule.
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The atomic number is:
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The number of protons in an atom of an element.
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The mass number is:
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The sum of the number of protons and neutrons in an element.
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Isotopes are:
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Atoms with the same atomic number, but different mass numbers. I.e. They have different numbers of neutrons.
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Radioactivity is:
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A property of unstable nuclei causing them to emit radiation spontaneously.
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Alpha radiation:
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A helium nucleus. +2 relative charge. The nucleus loses two protons and neutrons. It can be stopped by paper, and is not easily deflected by an electrical field.
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Beta radiation:
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High energy electrons with charge -1. The nucleus gains a proton and loses a neutron. These can be stopped by foil and deflected by electrical fields.
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Gamma radiation.
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A photon with no charge. The nucleus does not change. It takes a lead sheet to stop gamma radiation and cannot be deflected by electrical fields.
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Half-life is:
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The time taken for half the radioactive nuclei in a sample to decay OR the time taken for the radioactivity of a sample to reduce to half.
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Tracers are:
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Radioactive isotopes whose decay is monitored. Used in medicine for diagnosis. The half-life trace time should not be too long or too short. Tracers are considered relatively safe.
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Nuclear fusion is:
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The joining of two or more nuclei to create one more massive nucleus of a new element. Requires high temperatures and/or pressures.
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An energy level is:
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A discrete amount of energy an electron in an atomic orbital can possess. Energy levels increase further from the nucleus and get closer together.
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Absorption spectra are caused by:
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The absorption of specific frequencies of light by electrons in order to promote them to the next discrete energy level. Delta e = hv.
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Absorption spectra look like:
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A series of dark lines on a coloured background, getting closer at higher frequencies.
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Emission spectra are caused by:
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The re-emission of specific frequencies of light related to the discrete changed in energy they experience as they drop to lower energy levels. Related by delta e = hv.
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Emission spectra look like:
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A series of coloured lines on a dark background getting closer together at high frequencies.
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Metals and metals form:
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Metallic bonds.
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Metals and nonmetals form:
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Ionic bonds.
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Nonmetals and nonmetals form:
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Covalent bonds.
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Ionic lattices:
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Ionic bonding. High melting point. Usually soluble. Conductive in solution or if molten.
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Giant covalent networks:
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Covalent bonding. High melting point. Insoluble and non- conductive (except graphite)
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Simple molecular:
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Covalent bonding. Low melting points and usually insoluble. Non-conductive.
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Metallic lattices:
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Metallic bonding, high melting points, insoluble, conductive.
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Atoms in covalent bonding are held together by:
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Electrostatic attraction between the nuclei and the shared electrons. |
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Metallic bonding structure:
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A regular lattice of metal cations surrounded by a sea of delocalised electrons.
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The shape of a molecule is affected by:
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The number of electron groups around a central atom. The groups are involved in electrostatic repulsion and arrange themselves as far apart in space as possible.
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We arrange the periodic table by:
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Atomic number.
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Mendeleev arranged the periodic table by:
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Mass number.
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Periodicity is:
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The expression of a regular pattern of properties within a period of the periodic table. The regular pattern is then repeated in other periods.
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Formula for sulphuric acid:
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H2SO4 |
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Carbonate ions:
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CO3 2-
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Sulphate ions:
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SO4 2-
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Nitrate ions:
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NO3 -
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Ammonium ions:
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NH4 +
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Hydrogen carbonate ions:
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HCO3 -
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Group 2 metals react with water to give:
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The metal hydroxide M(OH)2 and hydrogen gas. Hydroxide may be solid or aqueous.
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Group 2 oxides react with water to give:
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A metal hydroxide.
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Group 2 oxides react with acids to give:
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A metal salt (aq) and water.
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Group 2 hydroxide solubility:
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Increases down the group.
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Group 2 carbonate solubility:
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Decreases down the group.
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Group 2 carbonates MCO3 decompose thermally to give:
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Metal oxide and carbon dioxide.
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Group 2 carbonates thermal stability:
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Increases down the group.
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The sample inlet
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Stage 1. Where sample is injected. May need to be vaporised if solid.
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The ionisation area
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Stage 2. CATIONS are made from molecules with an electron gun.
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Acceleration area
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Stage 3. Ions are accelerated to the same kinetic energy by an ELECTRIC field.
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Drift region
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Stage 4. A long vacuum in which ions travel and separate. Heavy ions take longer.
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Ion detector:
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Stage 5. Where ions are converted into a mass spectrum based on time of flight. Only positive ions are detected.
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The most massive peak on a mass spectrum is:
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The molecular ion.
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The highest peak on a mass spectrometer is:
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The base peak.
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Radiocarbon dating can be affected by:
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The addition of contaminants. The amount of carbon 12 in the formative atmosphere or geography. Provided the sample was not melted and reformed.
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What is meant by 'one mole' in terms of Avogadro's constant?
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The number of carbon 12 atoms in 12 grams of carbon 12: 6.02x10^23. This number if atoms in any mole of a substance.
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Features of an emission spectrum: (3)
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A series of lines (spectrum); coloured lines on a dark background; lines CONVERGE at HIGHER FREQUENCY.
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Periodicity is:
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The recurring trends in elemental properties seen in periods which are repeated in other periods.
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Elements of the same group have similar properties because of:
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The same number of electrons in their outer shells, hence they enter similar reactions.
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Group two hydroxide and carbonate solubility trends down the group:
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more soluble, less soluble.
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