College Physics Problem 1.32

Calculate the approximate number of atoms in a bacterium. Assume that the average mass of an atom in the bacterium is ten times the mass of a hydrogen atom. (Hint: The mass of a hydrogen atom is on the order of 10-27 kg; and the mass of a bacterium is on the order of 10-15 kg)


The number of atoms is

\displaystyle \text{no. of atoms}=\frac{m_{bact}}{10\:m_H}=\frac{10^{-15}}{10\left(10^{-27}\right)}=10^{11}\:\text{atoms}          ☚