What unit is commonly used to express density for solids?

• A. g/mL
• B. kg/m3
• C. g/L
• D. g/cm3

Answer: (D)

Density tells you how much mass is packed into a given volume, and for solids this is most conveniently expressed in grams per cubic centimeter. Using g/cm^3 fits well because a solid’s mass is often measured in grams and its volume in cubic centimeters with simple tools like rulers or water displacement. The numbers stay in a practical range for everyday solids, and it’s easy to compare different materials this way. Since 1 g/cm^3 equals 1000 kg/m^3, you can relate it to SI units if needed, bridging classroom practice with broader science. Other units exist: g/mL is effectively the same as g/cm^3 but is more common for liquids, and kg/m^3 is the SI unit but tends to give larger numbers that aren’t as handy for typical solid samples. Therefore, grams per cubic centimeter is the standard for solids.