chemistry

• Acid


  a substance with a pH of less than 7 that forms H+ ions in water
• activation energy


  the minimum amount of energy that reactant particles must have when they collide in order to react
• alkali


  a substance with a pH greater than 7 that forms OH- ions in solution
• alkali metal


  an element in group 1 of the periodic table
• alkane


  a saturated hydrocarbon with the general formula CnH2n+2
• alkene


  a type of hydrocarbon that is more reactive than alkanes
• alloy


  a metal that is a mixture of two or more metals, or a mixture involving metals and non-metals
• anion


  a particle with a negative charge, formed when one or more electrons are gained
• anomalous result


  a result that doesn't fit with the rest of the data
• aqueous


  when a substance is in solution with water
• atmosphere


  the layer of air that surrounds a planet
• atom


  a neutral particle made up of protons and neutrons in the nucleus, with electrons surrounding the nucleus
• atomic number


  the number of protons in the nucleus of an atom. proton number
• avogadro constant


  the number of particles in one mole of a substance, 6.02 x 10^23
• base


  a substance that reacts with acids in neutralisation reactions
• boiling


  the transition of a substance from a liquid to a gas
• boiling point


  the temperature at which a substance changes from a liquid to a gas or gas to liquid
• bond energy


  the amount of energy required to break a bond or the amount of energy released when a bond forms
• calibrate


  measure something with a known quantity and set the instrument being used to that quantity
• carbon footprint


  a measure of the amounts of greenhouse gases released by a product, service or event
• catalyst


  a substance that can speed up a reaction without being changed or used up
• cracking


  the process of breaking down long-chain hydrocarbons into shorter ones using a catalyst, often aluminium oxide
• categoric data


  data that comes in distinct categories
• cation


  a particle with a positive charge formed when one or more electrons are lost
• chemical bond


  the attraction of two atoms for each other, caused by the sharing or transfer of electrons
• chromatogram


  the pattern of spots formed as a result of separating a mixture using chromatography
• chromatography


  an analytical method used to separate the substances in a mixture based on how the components interact with a mobile phase and a stationary phase
• climate change


  a change in the Earth's climate
• collision theory


  the theory that in order for a reaction to occur particles must collide with sufficient energy
• combustion


  an exothermic reaction between a fuel and oxygen
• compound


  a substance made up of atoms of at least two different elements, chemically joined together
• concentration


  the amount of a substance in a certain volume of solution
• condensing


  the transition of a substance from a gas to a liquid
• continuous data


  numerical data that can have any value within a range
• control group


  a group that matches the one being studied, but where the independent variable isn't altered.
• control variable


  a variable in an experiment that is kept the same
• conversion factor


  a number which you must multiply or divide a unit by to convert it to a different unit
• correlation


  a relationship between two variables
• covalent bond


  a chemical bond formed when atoms share a pair of electrons
• covalent substance


  a substance where the atoms are held together by covalent bonds