Answer:
The answer is
7.80 g/cm³
Step-by-step explanation:
The density of a substance can be found by using the formula

From the question
mass = 156 g
1 mL = 1 cm³
20 mL = 20 cm³
volume = 20 cn³
The density of the metal is

We have the final answer as
7.80 g/cm³ to 3 significant figures
Hope this helps you