Neon has two isotopes. 90% of naturally occurring neon is neon-20 and 10% is neon-22.Relative Atomic Mass = (0.9 × 20) + (0.1 × 22) = 20.2Chlorine has two isotopes. 75.5% of naturally occurring chlorine is chlorine-35 and 24.5% is chlorine-37.Relative Atomic Mass = (0.755 × 35) + (0.245 × 37) = 35.5
Calculating Relative Atomic Mass
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Specification: OCR Chemistry A (H032), AS-level, 2.1.1 Atomic structure and isotopes. Topic: Atoms, Ions and Compounds.
Key terms in this lesson
- Isotopes
- Atoms of the same element with the same number of protons but different numbers of neutrons.
- Relative atomic mass
- The weighted mean mass of all the isotopes of an element compared to one-twelfth the mass of a carbon-12 atom.
More in Atoms, Ions and Compounds
- Carbon-12
- Relative Isotopic Mass
- Relative Atomic Mass
- The Mass Spectrometer
- Chemical Formulae
- Polyatomic ions
- Chemical Equations
- Electron Shells
All 17 lessons in Atoms, Ions and Compounds · All OCR AS-level Chemistry topics