Chlorine exists as ${ }^{35} \mathrm{Cl}$ (atomic mass $=34.9688 \mathrm{u} ; 75.77 \%$ ) and ${ }^{37}…
Chlorine exists as ${ }^{35} \mathrm{Cl}$ (atomic mass $=34.9688 \mathrm{u} ; 75.77 \%$ ) and ${ }^{37} \mathrm{Cl}$ (atomic mass $=36.9659 \mathrm{u} ; 24.23 \%$ ). The atomic mass of natural existing chlorine is