## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

The number density of particles in the solar corona is $1.09\times 10^{15}~particles/m^3$
We use the formula below to find the number of particles: $PV = NkT$ $\frac{N}{V} = \frac{P}{kT}$ $\frac{N}{V} = \frac{0.03~Pa}{(1.38\times 10^{-23}~J/K)(2\times 10^6~K)}$ $\frac{N}{V} = 1.09\times 10^{15}~particles/m^3$ The number density of particles in the solar corona is thus $1.09\times 10^{15}~particles/m^3$.