chemistry paper 1

• What topics are covered in AQA GCC chemistry paper 1?

  Atoms, bonding, quantitative chemistry, energy changes
• What is a compound?

  A substance with two or more different atoms bonded
• What is the chemical formula for water?

  H2O
• How many hydrogen atoms are in one water molecule?

  Two hydrogen atoms
• What does it mean if there is no number after a chemical symbol?

  It indicates an invisible one
• What do chemical reactions involve regarding atoms?

  Atoms change their bonds and how they are bonded
• What is a word equation?

  A representation of a chemical reaction using words
• Why must chemical equations be balanced?

  Atoms are not created or destroyed in reactions
• What is the first step in balancing a chemical equation?

  Balance atoms that are only in compounds
• How do you balance hydrogen atoms in a reaction?

  Put a number in front of the compound
• What is a mixture?

  A combination of elements and compounds not bonded
• What is an example of a mixture?

  Air
• How can you separate large insoluble particles from a liquid?

  Using filtration
• What is crystallization used for?

  To separate a solute from a solvent
• What does distillation involve?

  Heating a solution and cooling the gas
• What is fractional distillation used for?

  To separate liquids with different boiling points
• What are the three main states of matter?

  Solid, liquid, gas
• How do particles behave in a solid?

  They vibrate around fixed positions
• What happens to water when it is heated?

  It can melt or evaporate
• What do we call the process of a solid turning into a liquid?

  Melting
• What do we call the process of a liquid turning into a gas?

  Evaporation
• What indicates the state of a substance in a chemical equation?

  State symbols in brackets
• What does the letter 'l' represent in state symbols?

  Liquid
• What does the letter 's' represent in state symbols?

  Solid
• What does the letter 'g' represent in state symbols?

  Gas
• What does 'aq' stand for in state symbols?

  Aqueous or dissolved in solution
• Who proposed the plum pudding model of the atom?

  JJ Thompson
• What did Ernest Rutherford discover about the atom?

  The positive charge is in the nucleus
• What did Niels Bohr discover about electrons?

  They exist in shells or orbitals
• What are protons and neutrons collectively called?

  Nucleons
• What is the charge of a proton?

  Plus one
• What is the charge of a neutron?

  Zero
• What is the charge of an electron?

  Minus one
• What does the atomic number represent?

  The number of protons in the nucleus
• What does the mass number represent?

  The total number of protons and neutrons
• What happens when an atom gains or loses electrons?

  It becomes an ion
• What are isotopes?

  Atoms of the same element with different neutrons
• What is relative abundance?

  The percentage of each isotope in a sample
• How is the average relative atomic mass calculated?

  By averaging the masses of isotopes
• What did Dmitri Mendeleev contribute to the periodic table?

  Grouped elements by properties, not atomic weight