Problem: The element gallium (Ga) has the second largest liquid range of any element, melting at 29.78 oC and boiling at 2204 oC at atmospheric pressure.What is the density of gallium in g/cm3 at 25 oC if a 1 in cube has a mass of 0.2133 lb?

We’re being asked to determine the density of gallium (Ga).

Recall that density is the ratio of the mass and volume of an object:

$\boxed{\mathbf{density}\mathbf{=}\frac{\mathbf{mass}}{\mathbf{volume}}}$

Also, the volume of a sphere is given by:

$\boxed{\mathbf{V}\mathbf{=}{\mathbf{a}}^{\mathbf{3}}}$

where: 

a = edge length. 

In order to solve this problem we need to:

Step 1. Determine the volume
Step 2. Determine the mass in grams
Step 3. Calculate the density