C1 - Atomic structure

• What is chromatography used for?

  Separating a mixture of substances
• What are atoms?

  Smallest part of an element that can exist
• What is the approximate radius of an atom?

  0.1 nm
• What chemical symbol represents oxygen?

  O

  
• What is an element?

  Substance made of one type of atom
• What defines a compound?

  Contains two or more elements combined
• What is the chemical formula for carbon dioxide?

  CO2
• How can compounds be separated into elements?

  By chemical reactions only
• What must the first letter of a chemical symbol be if it has one letter?

  It must be capital
• What does a small number after an element symbol indicate?

  Number of atoms of that element
• What is crystallisation used for?

  Forming crystals from a solution
• What is distillation used for?

  Separating a mixture of liquids
• What does the distance travelled by a spot in chromatography depend on?

  Solubility of the substance
• Why must the pencil line be above the solvent in chromatography?

  To prevent dissolving into the solvent
• What is the purpose of filter paper in filtration?

  To separate insoluble solids from liquids
• What happens to small solute molecules in filtration?

  They pass through the filter paper
• What is the purpose of an evaporating basin?

  To evaporate water from a solution
• When should you stop heating a solution in crystallisation?

  When crystals appear
• What is the charge and mass of an electron?

  -1 charge, very small mass
• What is the charge and mass of a proton?

  +1 charge, mass of 1
• What is the charge and mass of a neutron?

  0 charge, mass of 1
• What does the atomic number represent?

  Number of protons in the atom
• What does the mass number represent?

  Number of protons plus neutrons
• How are electrons arranged in an atom?

  In shells around the nucleus

  
• How many electrons can the first shell hold?

  Up to 2 electrons
• How many electrons can the second shell hold?

  Up to 8 electrons
• How many electrons can the third shell hold?

  Up to 8 electrons
• What is the electron structure of oxygen?

  2,6

  
• What happens when atoms lose or gain electrons?

  They become charged ions

  
• What are isotopes?

  Atoms with same protons, different neutrons
• What is the order of naming compounds of two elements?

  Metal name first, non-metal second
• How does the non-metal name end in compound naming?

  Ends in -ide
• What is the word equation for calcium and bromine?

  Calcium + bromine → calcium bromide
• What is the symbol equation for calcium and bromine?

  Ca + Br2 → CaBr2
• What is true about the number of protons and electrons in an atom?

  They are equal in number
• What happens to the liquid with the lowest boiling point during distillation?

  It boils and condenses in the condenser
• What happens to liquids with higher boiling points during distillation?

  They are left in the flask
• What are the methods for separating mixtures?

  • Chromatography
  • Crystallisation
  • Distillation
  • Filtration
• What are the components of an atom?

  • Protons
  • Neutrons
  • Electrons
• What are the properties of ions?

  • Charged particles
  • Formed by loss or gain of electrons
  • Different number of protons and electrons