Chemistry 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
• 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 reactants and products
• 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
• How do you balance hydrogen atoms in a chemical equation?

  By placing a coefficient in front of the compound containing hydrogen to multiply the number of hydrogen atoms
• 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, which is a mixture of oxygen, nitrogen, and more
• How can you separate large insoluble particles from a liquid?

  Using filtration
• What is crystallization used for?

  To separate a solute from a solvent after evaporating the solvent
• 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
• How do particles behave in a gas?

  Particles are far apart and move randomly with high energy
• What is required to melt or evaporate a substance?

  Energy, usually in the form of heat, to overcome electrostatic forces of attraction between particles
• What do state symbols indicate in chemical equations?

  They 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 are neutrons and protons?

  Neutrons are neutral particles, and protons are positively charged particles in the nucleus
• What is the atomic number?

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

  It becomes an ion
• 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
• What is relative abundance?

  Relative abundance is the percentage of each isotope of an element found in nature
• How do you calculate the average relative atomic mass of chlorine?

  By taking the weighted average of the isotopes based on their relative abundance
• How was the periodic table originally organized?

  Elements were arranged in order of their atomic weights
• Who grouped elements based on their properties, leading to gaps in the periodic table?

  Dmitri Mendeleev
• How do electrons fill the shells around the nucleus?

  Electrons fill 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 alkali metals?

  Group 1 elements that have one electron in their outer shell
• How does reactivity change in alkali metals as you go down the group?

  Reactivity increases as you go down the group
• What are the halogens?

  Group 7 elements that have seven electrons in their outer shell
• How does reactivity change in halogens as you go down the group?

  Reactivity decreases as you go down the group
• What are noble gases?

  Group 0 elements that have a full outer shell and are very unreactive
• What happens to metals when they lose electrons?

  They become positively charged ions
• What charge do group 1 metals form when they become ions?

  They form +1 ions
• What charge do group 2 metals form when they become ions?

  They form +2 ions
• What charge do group 7 nonmetals form when they become ions?

  They form -1 ions