Use equation density = mass/volume
Known/Given
d= 10.5g/cm^3
v= 24.0 cm^3
Use that equation i just mentioned...
Solution
Rewrite the formula as the forumla for solving density into mass
Which is... mass = 10.5g/cm^3 × 24.0cm^3 = 252g
So thats the answer
252g
Hope i could help