Atomic Structure

• what is an atom


  most Basic unit of matter
• what is a molecule


  two or more atoms held together by covalent bonds
• Relative charge of a proton

  +1
• relative mass of a proton

  +1
• relative charge of a neutron

  0 (neutral)
• relative mass of a neutron

  +1
• relative charge of an electron


  -1 (negative)
• relative mass of an electron

  1/1836
• what is the atomic number

  number of protons in the nucleus
• what is the mass number


  the total number of protons and neutrons in a nucleus.
• what is an isotope


  Atoms of the same element that have different numbers of neutrons
• relative atomic mass with isotope abundance equation

  Ar = (% of isotope 1 x mass of isotope 1) + (% of isotope 2 x mass of isotope 2) / 100