The density of osmium (the densest metal) is 22.57 g/cm3. What is the mass of a block of osmium with dimensions:
4.22 cm x 3.62 cm x 1.41 cm?

 mass = 485 grams approximately

Work Shown:

First we need the volume of the block

volume = (length)*(width)*(height)

volume = (4.22)*(3.62)*(1.41)

volume = 21.539724

volume = 21.5 cubic cm

I'm rounding to three sig figs because each of the dimensions are to three sig figs.

Now turn to the formula

density = mass/volume

This can be rearranged to

mass = density*volume

Plug in the given density and the volume we found earlier to get

mass = density*volume

mass = (22.57)*(21.5)

mass = 485.255

mass = 485 grams

I'm rounding to three sig figs because it's the smaller sig fig count of 22.57 and 21.5