The density of brass is 8.4 g cm−3. What do you mean by this statement?
The density is defined as mass per unit volume.
This statement means one cubic centimetre volume of brass has a mass of 8.4 g.
What do you mean by this statement :
The density of iron is 7.8gm cm-3
'The density of iron is 7800 kg m−3'. What do you understand by this statement ?