Element

Isotope

Abundance

Isotope

Abundance

ratio / %

Hydrogen

¹H

99.985

²H

0.015

²H/¹H    0.015

Carbon

¹²C

98.893

¹³C

1.107

¹³C/¹²C     1.12

Nitrogen

¹⁴N

99.634

¹⁵N

0.366

¹⁵N/¹⁴N     0.37

Oxygen

¹⁶O

99.759

¹⁷O

0.037

¹⁷O/¹⁶O     0.04

¹⁸O

0.204

¹⁸O/¹⁶O     0.20

Sulfur

³²S

95.02

³³S

0.78

³³S/³²S      0.82

³⁴S

4.22

³⁴S/³²S      4.44

Chlorine

³⁵Cl

75.77

³⁷Cl

24.23

³⁷Cl/³⁵Cl    32.0

Bromine

⁷⁹Br

50.537

⁸¹Br

49.46

⁸¹Br/⁷⁹Br    97.9