paper 1

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

  Topics 1 to 5: atoms, bonding, quantitative chemistry, and chemical and energy changes
• What is a compound?

  A compound is a substance that contains two or more different types of atoms chemically bonded together
• What is the chemical formula for water?

  The chemical formula for water is H2O
• How many hydrogen atoms are in one molecule of water?

  There are two hydrogen atoms in one molecule of water
• What happens to atoms during a chemical reaction?

  Atoms change what they're bonded to and how they're bonded through chemical reactions
• What is a word equation?

  A word equation represents a chemical reaction using the names of the substances involved
• Why must chemical equations be balanced?

  Because atoms are not created or destroyed in a chemical reaction, the same number of each type of atom must be on both sides
• What is the first step in balancing a chemical equation?

  Start balancing atoms that are only in compounds
• What is a mixture?

  A mixture is any combination of different types of elements and compounds that aren't chemically bonded together
• What is an example of a mixture?

  Air is a mixture of oxygen, nitrogen, and more
• How can large insoluble particles be separated from a liquid?

  By using filtration
• What is crystallization?

  Crystallization leaves a solute behind after evaporating the solvent from a solution
• What is distillation?

  Distillation involves heating a solution and cooling the gas to condense it back into a liquid
• What is fractional distillation?

  Fractional distillation separates different liquids in a mixture based on their boiling points
• What are the three main states of matter?

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

  Particles vibrate around fixed positions in a solid
• What happens to particles when a substance melts or evaporates?

  Energy must be supplied to overcome the electrostatic forces of attraction between the particles
• What do state symbols indicate in chemical equations?

  State symbols indicate the physical state of substances: (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous
• Who proposed the plum pudding model of the atom?

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

  He discovered that the positive charge is concentrated in a small nucleus
• What did Niels Bohr contribute to atomic theory?

  Niels Bohr discovered that electrons exist in shells or orbitals around the nucleus
• What are protons and neutrons collectively called?

  They are called nucleons
• What is the charge of a proton and an electron?

  Protons have a charge of +1 and electrons have a charge of -1
• What does the atomic number represent?

  The atomic number represents the number of protons in the nucleus
• What is an ion?

  An ion is an atom that has gained or lost electrons
• What is the mass number?

  The mass number is the total number of protons and neutrons in the nucleus
• What are isotopes?

  Isotopes are atoms of the same element with different numbers of neutrons
• How is the average relative atomic mass calculated?

  By taking the weighted average of the masses of all isotopes of an element
• What did Dmitri Mendeleev contribute to the periodic table?

  Dmitri Mendeleev grouped elements based on their properties and predicted undiscovered elements
• How do electrons fill the shells around the nucleus?

  Electrons fill the shells from the inside out, with a maximum of 2 in the first shell and 8 in the second and third shells
• What are the properties of metals?

  Metals are good conductors of electricity and heat and tend to lose electrons to form positive ions
• What is ionic bonding?

  Ionic bonding occurs when a metal atom loses electrons and a non-metal atom gains electrons
• What must the charges of all ions in an ionic compound do?

  The charges must add up to zero
• What is a lattice structure in ionic compounds?

  A lattice structure consists of repeating units of ions forming a crystal
• Why do ionic compounds have high melting and boiling points?

  Because of the strong electrostatic forces that need to be overcome
• When can ionic compounds conduct electricity?

  Ionic compounds can conduct electricity when they are molten or dissolved in solution
• What is covalent bonding?

  Covalent bonding occurs when non-metal atoms share electrons to gain full outer shells
• What are simple molecular structures?

  Simple molecular structures consist of individual molecules that can mix together
• Why do simple molecular structures have low boiling points?

  Because there are only weak intermolecular forces between the molecules
• What is giant covalent bonding?

  Giant covalent bonding involves atoms forming covalent bonds to create a giant structure