Question

Problem 1 A rectangular piece of material measures 1.5 cm by 2.0 cm by 2.5 cm. The mass of this material is 144.9 g. What element is the material made out of?

Density of Aluminum = 2.70 g/cm,

Density of Iron = 7.87 g/cm

Density of Lead = 11.36 g/cm

Density of Gold = 19.32 g/cm

Answer 1

The mass of the rectangular piece of material is

And the volume of the rectangular piece is
  
So, the density of a material is defined by
  
So, putting the given values, we get

  
This matches with the density of Gold. So, we can conclude that the material is made out of Gold.