C2 topic 1: Isotopes and relative atomic mass

C2 topic 1: Isotopes and relative atomic mass

1. Isotopes

   • *Different forms of the same element, which have the same number of protons but different number of neutrons.

2. Protons

   • Same number of protons-different mass number (neutrons)
   • A different number of protons would mean a different element

3. Relative atomic mass takes isotopes into account

   • Relative atomic mas (Ar) uses average mass of isotope of element
   • Has to allow for relative mass of each isotope and its relative abundance.
   • Relative abundance=How much of each isotope compared to the total amount in the world.

4. Relative atomic mass

   • 1. Multiply each mass of each isotope by its relative abundance.
   • 2. Add together
   • 3. Add relative abundances together
   • 4. Divide by the sum of relative abundances