Atomic structure

• Atom


  smallest unit of matter

  contains protons, neutrons and electeons
• atomic structure 


  electrons: moves around nucleus, negatively charged, no mass

  nucleus: contains protons and neutron, positively charged, whole mass

  
• protons


  relative mass: 1

  relative charged: +1

  heavy

  positive charged
• neutrons 


  relative mass: 1

  relative charge: 0

  heavy

  neutral
• electrons


  relative mass: very small

  relative charge: -1

  tiny

  negative charged
• positive ions

  they are negative
• negative ions

  they are positive
• atomic number

  number of protons
• mass number

  number of protons + neutrons
• number of electrons

  mass number - atomic number