Question

What is the number density of (a) aluminium and (b) lead?

Short answer

It deals with the density of lead and aluminium and the atoms bounded in the system

Step-by-step solution

Description of the temperature and density of lead and aluminium.

The density depends on the temperature and amount of substances within these objects.

Explanation on the solution 

Provided solution

$$\begin{gathered} P=\frac{m}{v} \\ V=\frac{m}{p} \\ \frac{N}{V}=\frac{M/m}{M/p}=\frac{p}{m} \\ m=27\mu \times \frac{1.66\times {10}^{-27kg}}{1\mu }=4.48\times {10}^{-26kg} \\ \frac{ppb}{m} \\ =\frac{11300kg/m^3}{3.43\times {10}^{-25kg}} \end{gathered}$$