Answer:
The answer is
7.80 g/cm³
Step-by-step explanation:
The density of a substance can be found by using the formula
![density = (mass)/(volume) \\](https://img.qammunity.org/2021/formulas/chemistry/college/2qztd1zu9lpwav17leag2cjjn695yipoje.png)
From the question
mass = 156 g
1 mL = 1 cm³
20 mL = 20 cm³
volume = 20 cn³
The density of the metal is
![density = (156)/(20) = (39)/(5) \\](https://img.qammunity.org/2021/formulas/chemistry/high-school/xifgf77sjdw2yj2h47epaaiwah50py8e6x.png)
We have the final answer as
7.80 g/cm³ to 3 significant figures
Hope this helps you