Isotopes

• What are isotopes?

  Isotopes are different forms of the same element.

  Isotopes are atoms of the same element with different numbers of neutrons but the same number of protons (and electrons).

  
• Isotopes

  The mass number is DIFFERENT; the atomic number is the SAME
• Relative Atomic Mass = $\frac{sum\ of\ \left(abundance\times isotope\ mass\right)}{100}$
• Example - The abundance Cl - 35 is 75% and Cl - 37 is 25%

  Relative mass = $\frac{abundance\times mass}{100}$

  =\frac{\left(75\times35\right)\ +\left(25\times37\right)}{100}=$\frac{2625+925}{100}$= 35.5