Atoms

• What is the radius of an atom?


  0.1 nanometres (1 x 10^-10 m)
• What is the radius of the nucleus?


  1 x 10^-14 m
• How much larger is the radius of an atom than the nucleus?


  10000
• What does the nucleus contain?


  Protons and Neutrons
• Is the nucleus positively or negatively charged?


  Positively charged
• Where are electrons in an atom?


  Moving around the nucleus in electron shells
• Relative mass of a proton?


  1
• Relative mass of a neutron?


  1
• Relative mass of an electron?


  very small or 0
• charge of a proton?


  +1
• charge of a neutron?


  0
• charge of an electron?


  -1
• Why do atoms have no charge?

  Because they have the same number of protons and electrons so their charges cancel out
• What is an atom that has lost or gained electrons


  An ion
• Which number is the atomic number?


  11

  
• What does the atomic mass tell you?


  How many protons and neutrons are in an atom
• What does the atomic number tell you?


  How many protons are in an atom
• How can you find the number of neutrons in an atom?


  Subtract the atomic number from the atomic mass