The energy of a spray

A spray breaks $1.0\ \text{cm}^3$ of water into tiny droplets, all the same size. The smaller the droplets, the more surface there is, and every square metre of new surface costs energy. You will make the program find the number of droplets, their total surface and the energy needed, for droplets from $1\ \text{mm}$ down to $1\ \mu\text{m}$ in radius.

The idea. Each droplet holds $\tfrac43\pi r^3$, so there are $N = \dfrac{V}{\frac43\pi r^3}$ of them, with a total surface $N \times 4\pi r^2 = \dfrac{3V}{r}$. The energy is $S$ times that surface.

Your tasks.

1. Work out the number of droplets N for every radius in r.
2. Work out their total surface area.
3. Work out the energy E needed, and read it off for droplets of radius $10\ \mu\text{m}$.