Hey the density of the material that has the mass of 52.45 g and a volume of 13.5 cm

Density has a formula of p=m/V

p= density

m= mass

V= volume (*make sure it is a capital V*)

So plug in what we know:

m= 52.45g

V= 13.5 cm

So now plug it into the formula

p= 52.45g/13.5 cm

and solve to get:

4.03333 g/cm

The 3 is repeating so make sure to adjust for significant figures if that applies.  

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.