Two stones resembling diamonds are suspected of being fakes. To determine if the stones might be real, the mass and volume of each are measured. Both stones have the same volume, 0.15 cm^3. However, stone A has a mass of 0.52 g, and stone B has a mass of 0.42 g.
A) If diamond has a density of 3.5 g/cm^3, could either of the stones be real diamonds? Explain.

Measuring density is an easiest way to determine if two similar looking substances are same or not. Here also we need to perform the density test for each stone that is suspected to be fake diamond. We will calculate the density of each stone and compare it with the density of original diamond.

Density is calculated using the formula

[tex]Density=\frac{Mass}{Volume}[/tex]

It has been given in the question that both the substances have same volume of 0.15 [tex]cm^3[/tex].

Density of stone A = [tex]\frac{0.52}{0.15}[/tex] = 3.47 [tex]gcm^-^3[/tex] or after rounding off we get 3.5 [tex]gcm^-^3[/tex]

Density of stone B = [tex]\frac{0.42}{0.15}[/tex] = 2.8 [tex]gcm^-^3[/tex]

It is clear from the above calculation that the stone A has same density as the diamond but stone B lacks behind in density.

So, stone A could be the real diamond.