Science 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
• What is the chemical formula for water?

  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 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 present 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
• Give an example of a mixture.

  Air, which is a mixture of oxygen, nitrogen, and more
• What is filtration used for?

  Filtration is used to separate large insoluble particles from a liquid
• What is crystallization?

  Crystallization is a process that leaves a solute behind after evaporating the solvent from a solution
• How does distillation work?

  Distillation involves heating a solution to create gas, which is then cooled to condense 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 state?

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

  Energy is 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 proposed the plum pudding model of the atom
• 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?

  Protons and neutrons are collectively called nucleons
• What is the charge of a proton?

  The charge of a proton is +1
• What is the charge of a neutron?

  The charge of a neutron is 0
• What is the charge of an electron?

  The charge of an electron is -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 does the mass number represent?

  The mass number represents 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 atomic mass (RAM)?

  Relative atomic mass is the weighted average mass of an element's isotopes
• How is the average relative atomic mass calculated?

  By adding the total masses of all isotopes and dividing by the total number of atoms
• What is the significance of Dmitri Mendeleev's periodic table?

  Mendeleev grouped elements based on their properties, predicting gaps for undiscovered elements
• How are electrons arranged in an atom?

  Electrons are arranged in shells around the nucleus
• What is the maximum number of electrons in the first four shells?

  The maximum number of electrons is 2 in the first shell, 8 in the second and third shells, and 2 in the fourth shell
• What are the properties of metals?

  Metals are good conductors of electricity and heat, and they lose electrons to form positive ions
• What are the properties of nonmetals?

  Nonmetals gain electrons to form negative ions and are generally poor conductors of electricity
• What are alkali metals?

  Alkali metals are in group one and 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 due to weaker electrostatic attraction
• What are halogens?

  Halogens are in group seven and have seven electrons in their outer shell