Elements

• Element


  Substance in which all atoms are the same (one 'type' of atom, same atomic number). an element cannot be broken down further by chemical means
• Relative atomic mass

  This is recorded underneath the symbol for the element on the periodic table and shows the average of the mass of each isotope of that element.
• Elements are arranged in the periodic table in order of increasing atomic number
• What are groups in the periodic table?

  Vertical columns
• Elements in the same group have similar chemical properties
• Structure of an atom


  Locations, relative masses and relative charges of sub-atomic particles (protons, neutrons and electrons)
• atomic number

  the number of protons
• isotopes

  two atoms that have the same number of protons but a different number of neutrons. They have the same atomic number but a different atomic mass.
• Calculating relative atomic mass


  From the percentage abundances of each isotope
• Electronic configuration of a main group element


  Related to its location in the periodic table (group number and period number)
• Compound


  a pure substance that contains two or more elements/types of atom that have chemically bonded together
• What happens to atoms in chemical reactions

  Rearranged to create new substances
• Naming simple compounds


  Formed from two different elements, such as sodium chloride (you do not need name compounds ending in -ate, such as copper sulfate)
• Chemical formula


  Represents a compound containing atoms of different elements bonded together in a fixed ratio
• Molecule


  Contains a fixed number of atoms of each element (represented by the chemical formula) which are chemically bonded together
• What are periods in the periodic table?

  Horizontal rows
• mixture

  a substance made up of two or more elements or compounds that are not chemically combined.
• RAM = (mass number of isotope x abundance)+(mass number of isotope x abundance)/100
• atomic mass


  the number of protons and neutrons
• charge of an atom

  zero - number of protons and electrons are the same so they cancel each other out.