Atomic structure & the periodic table ♡

Cards (41)

  • What are the subatomic particles in an atom?
    Protons, neutrons, and electrons
  • Where is the nucleus in an atom?
    In the centre
  • The nucleus has positive charge because of the protons (positive charge) and the neutrons (negative charge)
  • What is the relative mass of each subatomic particle? :
    protons = 1
    neutrons = 1
    electrons = very small or 0
  • What is the charge of each subatomic particle?:
    proton = +1
    neutron = no charge
    electron = -1
  • The volume of the electron's orbit determines the size of the atom
  • Why don't atoms have charge overall?
    They have the same number of protons and electrons
  • The charge on the electrons is the same size as the charge on the protons but, opposite - so the charges cancel out
  • The nuclear symbol of an atom tells you its atomic (proton) number and mass number
  • What tells you how many protons there are?
    The atomic number
  • How can you find the number of neutrons in an atom?
    Mass number - atomic number
  • How can you find the number of electrons in an atom?

    The atomic number
  • PRACTISE QUESTION:
    An atom of gallium has an atomic number of 31 and a mass number of 70. Give the number of electrons, protons and neutrons in the atom.
    Electrons = 31
    Protons = 31
    Neutrons = 12
  • An element is a substance that has only one type of atom
  • The number of protons in the nucleus decides what type of atom it is
    • An atom with one proton in its nucleus is HYDROGEN and an atom with two protons is HELIUM
  • Isotopes are different forms of the same element with the same number of protons but different number of neutrons
  • Isotopes have the same atomic number but different mass numbers
  • Relative atomic mass formula = sum of (isotope abundance × isotope mass number) / 100
  • PRACTISE QUESTION:
    A substance consists of atoms which all have the same number of protons and electrons but different numbers of neutrons. Explain why this substance is an element
    The number of protons in an atom determines what type of atom it is, so if all the atoms have the same number of protons then the substance is an element
  • PRACTISE QUESTIONS:
    Si-28 has an abundance of 92.2%, Si-29 has an abundance of 4.7% and Si-30 has an abundance of 3.1%. Calculate silicon's relative atomic mass to 1 decimal place
    28.1
  • An element is a pure substance made from only one type of atom
  • A compound is a substance made up of two or more elements chemically bonded together
  • What is the compound for each element given?
    1. Iron + Sulphur -> Iron sulphide
    2. Magnesium + Chlorine -> Magnesium chloride
    3. Sodium + Chlorine -> Sodium chloride
    4. Zinc + Sulphur -> Zinc sulphide
    5. Nickel + Sulphur + Oxygen -> Nickel sulphate
    6. Sodium + Nitrogen + Oxygen -> Sodium nitrate
    7. Aluminium + Bromine + Oxygen -> Aluminium bromate
  • Match the name of the compound to its chemical formula:
    • Magnesium fluoride -> MgF2
    • Carbon dioxide -> CO2
    • Aluminium oxide -> Al2O3
    • Lithium carbonate -> Li2CO3
    • Lithium oxide -> Li2O
    • Lithium hydroxide -> LiOH
    • Sulphuric acid ->H₂SO₄
    • Hydrogen -> H₂
  • Useful Chemical formulas:
    • Carbon dioxide - CO₂
    • Ammonia - NH3
    • Water - H₂O
    • Sodium Chloride - NaCl
    • Carbon Monoxide - CO
    • Hydrochloric acid - HCl
    • Calcium chloride - CaCl₂
    • Sodium carbonate - Na₂CO₃
    • Sulfuric acid - H₂SO₄
  • PRACTISE QUESTIONS:
    1. Balance the equation: Fe + Cl -> FeCl3
    2. Hydrogen and oxygen molecules are formed in a reaction where water splits apart.
    a) State the word equation b) Give a balanced word equation
    ANSWERS:
    1. 2Fe + 3Cl₂ -> 2FeCl3
    2. a) water -> hydrogen + oxygen b) 2H₂O -> 2H₂ + O₂
  • Alkali metals are in group 1 of the periodic table
  • The alkali metals have one electron in their outer shell, which makes them very reactive.
  • The more reactive the metal, the more likely it is to form a positive ion
  • Noble gases contain the least reactive elements because they have a full outer shell of electrons so they are inert (very unreactive)
  • Alkali metals have a low density
  • Halogens are in group 7
  • If sodium is burned in chlorine gas a compound is formed and this compound will dissolve in water
  • Distillation is used to separate a solvent from a solution
  • The order of when the subatomic particles were discovered:
    1. electrons
    2. protons
    3. neutrons
  • When elements react, electrons are given away, taken or shared
  • Lithium has a lower melting point than cobalt because cobalt is a transition metal and lithium is a group 1 metal, and transition metals have higher melting points than group 1 metals.
  • Three properties that transition metals share with other metals are: Dense, strong and good electrical conductors
  • You can tell from their positions in the periodic table than manganese is more dense than potassium because manganese is a transition metals and potassium is in group 1. Transition metals have a higher density than group 1 metals.
  • In the alpha particle scattering experiment they expected most of the particles to travel straight through the gold sheet, with some particles changing direction by a small amount. However, some alpha particles were deflected more than expected, meaning there must be a greater concentration of positive charge in the atom than you’d get with the plum pudding model.