Calculate density, mass, or volume of materials and check density references.
| Material | Density |
|---|---|
| Water | 1.00 g/cm³ |
| Iron | 7.87 g/cm³ |
| Aluminum | 2.70 g/cm³ |
| Copper | 8.96 g/cm³ |
| Gold | 19.32 g/cm³ |
Density (ρ) is mass per unit volume, representing an intrinsic property of matter. Formula: Density (ρ) = Mass (m) ÷ Volume (V). Units include g/cm³, kg/m³, g/mL. Water density is 1 g/cm³ = 1000 kg/m³, serving as the reference standard. High density means more mass in the same volume. Iron density is 7.87 g/cm³ (8× heavier than water), aluminum is 2.70 g/cm³, and gold is 19.32 g/cm³ (19× heavier than water).
Example 1 (Find Density): Object with mass 500g and volume 200cm³: ρ = 500 ÷ 200 = 2.5 g/cm³. Example 2 (Find Mass): Iron (density 7.87 g/cm³), volume 100cm³: m = 7.87 × 100 = 787g. Example 3 (Find Volume): Gold (density 19.32 g/cm³), mass 1000g: V = 1000 ÷ 19.32 = 51.76cm³.
Common Metals: Aluminum 2.70 g/cm³, Iron 7.87 g/cm³, Copper 8.96 g/cm³, Zinc 7.14 g/cm³, Lead 11.34 g/cm³. Precious Metals: Gold 19.32 g/cm³, Platinum 21.45 g/cm³, Silver 10.49 g/cm³. Non-metals: Water 1.0 g/cm³, Ice 0.92 g/cm³, Glass 2.5 g/cm³, Concrete 2.3~2.4 g/cm³.
According to Archimedes Principle, buoyant force equals the weight of displaced fluid. Objects with density less than 1 g/cm³ float in water, while denser objects sink. Wood (0.5~0.6 g/cm³) floats, iron (7.87 g/cm³) sinks. Ice (0.92 g/cm³) floats because its density is lower than water (1.0 g/cm³). Ships float because their average density (including air space) is less than water.
1. Direct Method: Measure mass with a scale, measure volume with a graduated cylinder. Density = Mass ÷ Volume. 2. Pycnometer: Precision volume bottle for accurate liquid density measurement. 3. Hydrometer: Float device reading a density scale, used for battery electrolyte and milk testing. 4. Digital Density Meter: Vibrating tube principle with 0.0001 g/cm³ precision.
Material Selection: Aircraft use lightweight aluminum alloys (2.7 g/cm³), cars use steel (7.9 g/cm³) and plastics (1.0~1.5 g/cm³). Quality Testing: Gold purity testing by density measurement, pure gold (19.32 g/cm³) vs. alloys. Medical: Bone density testing for osteoporosis diagnosis. Construction: Concrete density (2.3 g/cm³) for quality control. Food: Milk density (1.03 g/cm³) to detect water dilution.