CIE AS Chemistry (9701) exams from 2022

Revision Notes

4.1.3 Isotopic Abundance & Relative Atomic Mass

Calculating Relative Atomic Mass

  • Isotopes are different atoms of the same element that contain the same number of protons and electrons but a different number of neutrons.
    • These are atoms of the same elements but with different mass numbers
  • Because of this, the mass of an element is given as relative atomic mass (Ar) by using the average mass of the isotopes
  • The relative atomic mass of an element can be calculated by using the relative abundance values
    • The relative abundance of an isotope is either given or can be read off the mass spectrum

Calculating Relative Atomic Mass equation 1

Worked example: Calculating relative atomic mass of oxygen

Analytical Techniques Worked example - Calculating relative atomic mass of oxygen, downloadable AS & A Level Chemistry revision notes

Answer 

The correct answer is 1

Calculating Relative Atomic Mass worked example equation 1

= 16.0044

= 16.00

Worked example: Calculating relative atomic mass of boron

Analytical Techniques Worked example - Calculating relative atomic mass of boron, downloadable AS & A Level Chemistry revision notes

Analytical Techniques Mass Spectrum Boron, downloadable AS & A Level Chemistry revision notes

Answer

 Calculating Relative Atomic Mass worked example equation 2

Close

Join Save My Exams

Download all our Revision Notes as PDFs

Try a Free Sample of our revision notes as a printable PDF.

Join Now
Go to Top