Summary 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 symbol in a chemical formula?

  It indicates an invisible one atom
• 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 sand from water?

  Using filtration
• What is crystallization used for?

  To separate a solute from a solution
• What is distillation?

  Heating a solution to separate liquids
• What is fractional distillation?

  Separating 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 particles when a substance melts?

  They gain energy to overcome attractions
• What do state symbols indicate in chemical equations?

  The state of substances involved
• What does 's' represent in state symbols?

  Solid
• What does 'l' represent in state symbols?

  Liquid
• What does 'g' represent in state symbols?

  Gas
• What does 'aq' represent in state symbols?

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

  JJ Thompson
• What did Rutherford discover about the atom?

  It has a small, dense nucleus
• What are electrons said to exist in?

  Shells or orbitals
• What are protons and neutrons' relative mass?

  One
• What is the charge of a proton?

  Plus one
• What is the charge of an electron?

  Minus one
• What does the atomic number represent?

  The number of protons in the nucleus
• What happens when an atom gains or loses electrons?

  It becomes an ion
• What does the mass number indicate?

  Number of protons and neutrons in the nucleus
• 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 just weight
• How do electrons fill the shells around the nucleus?

  From the inside out, with specific maximums
• What is the maximum number of electrons in the first shell?

  Two electrons
• What is the maximum number of electrons in the second shell?

  Eight electrons