GCSE Chemistry (AQA)

196 videos | 19 hours

Atomic structure and the periodic table A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes

Atoms & Elements

2:05 Atoms, Elements and Compounds
Spec 4.1.1.1
Next Compounds
  • The smallest part of a substance that can exist is an atom.
  • Atoms make up everything around us.
  • Example: A pen is made up of incredibly small particles, which are atoms.
  • A substance containing only one type of atom is known as an element.
  • Examples of elements:
  • Gold (gold bar consists of only gold atoms)
  • Helium (gas in a helium balloon consists of helium atoms)
  • Atoms of each element are represented by a chemical symbol.
  • Symbols start with an uppercase letter; any further letters are lowercase.
  • Example:
  • "O" is the chemical symbol for oxygen.
  • "Na" is the chemical symbol for sodium (N is uppercase, a is lowercase).
  • Important to remember the rules for writing symbols for exams.
  • All elements can be found in the periodic table.
  • The periodic table shows chemical symbols for various elements arranged in a specific way.
  • Need to recall that there are approximately a hundred different elements in the periodic table for exams.

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