Answer: The unknown metal will be Copper.
Step-by-step explanation:
We are given an object of unknown metal having dimensions: 4 cm long, 1.5cm wide and 1.4 cm tall.
So, the volume of the object will be:

To identify the unknown metal, we compare the calculated density with the specific density of metals.
Now, to calculate the density of an object, we use the formula:

We are given:
Density of unknown metal = ?
Mass of unknown metal = 75 g
Volume of unknown metal =
Putting values in above equation, we get:


The calculate density matches the specific density of Copper metal.
Hence, the object is copper metal.