BIO Estimate the number of atoms in your body. (?Hint?: Based on what you know about biology and chemistry, what are the most common types of atom in your body? What is the mass of each type of atom? Appendix D gives the atomic masses of different elements, measured in atomic mass units; you can find the value of an atomic mass unit, or 1 u, in Appendix E.)
Solution 61P The most common types of atoms in our body is oxygen and hydrogen. Now since the hydrogen atoms are very light, we can consider that body is mainly made by oxygen. Now the mass of oxygen is 16 u = 16 × (1.66 × 10 27 kg) = 2.66 × 10 26kg. The average mass of a person is around 60 kg. 60 kg So the number of atoms in the body is then n = 26 = 2.26 × 10 27. 2.66×10 kg 27 So the number of atoms in our body is of the order of 10 number.