chemistry: atomic structure

    Cards (36)

    • Chromatography
      To separate out mixtures
    • Evaporation
      To separate a soluble salt from a solution; a quick way of separating out the salt
    • Filtration
      To separate solids from liquids
    • Crystallisation
      To separate a soluble salt from a solution; a slower method of separating out salt
    • Distillation
      To separate out mixtures of liquids
    • Simple distillation
      Separating a liquid from a solution
    • Fractional distillation
      Separating out a mixture of liquids. Fractional distillation can be used to separate out crude oil into fractions
    • Atoms
      • Contained in the nucleus are the protons and neutrons
      • Moving around the nucleus are the electron shells
      • They are negatively charged
    • Overall, atoms have no charge; they have the same number of protons as electrons
    • Ion
      A charged particle - it does not have an equal number of protons to electrons
    • Atomic Number

      The number of protons in the nucleus of an atom
    • Mass Number

      The total number of protons and neutrons in the nucleus of an atom
    • To calculate the relative atomic mass
      Equation: relative atomic mass (Ar) = sum of (isotope abundance × isotope mass number) / sum of abundances of all isotopes
    • Balancing Symbol Equations
      There must be the same number of atoms on both sides of the equation
    • Balanced equation
      • CH4 + 2O2 -> 2H2O + CO2
    • Elements
      Made of atoms with the same atomic number
    • Isotopes
      Elements with the same number of protons but different numbers of neutrons
    • Compounds
      When two or more elements are chemically joined, held together by chemical bonds and difficult to separate
    • Compound formulas
      • CO2
      • NaCl
      • HCl
      • H2O
      • Na2SO4
    • Chemical Reaction
      • Can be shown by a word equation or a symbol equation
      • Reactants on the left, products on the right
    • Equations need to be balanced, so the same number of atoms are on each side
    • To balance equations, numbers are put in front of the compounds
    • Metals
      • Strong, malleable, good conductors of electricity and heat, bond metallically
    • Non-Metals
      • Dull, brittle, not always solids at room temperature
    • Metals are found at the left part of the periodic table, non-metals are at the right
    • Alkali Metals

      Group 1 elements, soft, very reactive metals with one electron in their outer shell
    • Alkali metal reactions
      1. Reaction with water to produce hydrogen
      2. Reaction with chlorine to produce a metal salt
      3. Reaction with oxygen to form metal oxides
    • Halogens
      Group 7 non-metal elements (fluorine, chlorine, bromine, iodine) that become less reactive going down the group
    • Noble Gases
      Group 0 elements (helium, neon, argon) that are unreactive due to full outer shells
    • Electronic Structure
      Electrons are found in shells, with a maximum of 2 in the innermost shell, then 8 in the 2nd and 3rd shells
    • The inner shell is filled first, then the 2nd then the 3rd shell
    • History of the Atom
      • John Dalton - atoms described as solid spheres
      • JJ Thomson - plum pudding model
      • Ernest Rutherford - alpha scattering experiment
      • Niels Bohr - electrons in shells orbiting nucleus
      • James Chadwick - discovered neutrons in nucleus
    • The periodic table was not complete in the early 1800s as some elements had not been found
    • Mendeleev left gaps in the periodic table, believing there were undiscovered elements which were later found to fit the pattern
    • Modern Periodic Table
      • Elements in order of atomic mass/proton number
      • Shows where metals and non-metals are
      • Columns are groups, showing number of outer shell electrons
      • Rows are periods, showing full electron shells
    • The periodic table can be used to predict the reactivity of elements
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