Chemistry

• What are the alkali metals?

  The elements in Group 1 of the periodic table.
• What is an atom?

  The smallest part of an element that can exist.
• What is the atomic nucleus composed of?

  Protons and neutrons.
• What is the atomic number?

  The number of protons in the nucleus.
• What is chromatography used for?

  To separate a mixture of chemicals by distributing the components between two phases.
• What is a compound?

  A substance made up of two or more types of atoms chemically combined together.
• What is crystallisation used for?

  To produce solid crystals from a solution by evaporating the solvent.
• What does displacement refer to in chemistry?

  A chemical reaction in which a more reactive element displaces a less reactive element from its compound.
• What is an electron?

  A negatively charged subatomic particle that orbits the nucleus.
• What are electron shells?

  Different energy levels in atoms occupied by electrons.
• What is an element?

  A substance made up of only one type of atom.
• What is filtration used for?

  To separate solids from liquids.
• What is fractional distillation?

  A method of separating a mixture of substances according to their different boiling points.