Question 1

What is the formula for density?

Accepted Answer

Density ρ = mass ÷ volume (ρ = m/V). Rearrangements: mass = ρ × V, and volume = m ÷ ρ. The SI unit of density is kg/m³ but g/cm³ is common for solids and liquids.

Question 2

What is the density of water?

Accepted Answer

Pure water has a density of about 1.00 g/cm³ (1000 kg/m³) at 4°C. Ice is less dense (0.917 g/cm³), which is why it floats. Seawater averages 1.025 g/cm³ due to dissolved salts.

Question 3

How do I convert g/cm³ to kg/m³?

Accepted Answer

Multiply by 1000: 1 g/cm³ = 1000 kg/m³. So iron at 7.87 g/cm³ equals 7870 kg/m³. The reverse conversion (kg/m³ to g/cm³) divides by 1000.

Question 4

Can I use this for gases and liquids?

Accepted Answer

Yes. The same formula ρ = m/V applies to solids, liquids and gases. Gas densities are much lower (air ≈ 0.001225 g/cm³) and change with temperature and pressure.