Key ideas

• What are the key ideas in chemistry that describe the natural world?


  A small number of key ideas that are of universal application
• Why are the key ideas in chemistry important for science assessment?


  They underpin many aspects of the science assessment and will be assessed across all papers
• What is matter composed of?


  • Tiny particles called atoms
  • About 100 different naturally occurring types called elements
• What are elements in terms of their properties?


  Elements show periodic relationships in their chemical and physical properties
• How can periodic properties of elements be explained?


  In terms of the atomic structure of the elements
• How do atoms bond with each other?


  By either transferring electrons or sharing electrons
• Why are the shapes of molecules important?


  • They determine how molecules behave
  • They are influenced by the arrangement of giant structures
• What affects the rates of chemical reactions?


  There are barriers to reaction that cause reactions to occur at different rates
• What are the three different ways chemical reactions take place?


  1. Proton transfer
  2. Electron transfer
  3. Electron sharing
• What is the principle of energy conservation in chemical reactions?


  Energy is conserved and can neither be created nor destroyed
• What examination board is mentioned in the study material?

  AQA
• What is the phrase "Become an examiner" referring to?


  It suggests a call to action for individuals to engage with the examination process