1. Density Notes

2. What is density? Density – mass per unit volume What does per mean? – Examples that use per: miles per hour meters per second $ per pound – Example:50 miles per hour 50 miles are driven for every hour you go 100 miles are driven in 2 hours 100 miles ÷ 2 hours = 50 miles per hour – Per means divide.

3. density = mass per volume density = mass ÷ volume Example: mass = 14 gvolume = 12 mL14 ÷ 12 = 1.17 g/mL Example: mass = 190 gvolume = 92 mL190 ÷ 92 = 2.06 g/mL Example: mass = 65 gvolume = 98mL65 ÷ 98 = 0.66 g/mL

4. When a density is greater than one, the object will sink when placed in water. When a density is less than one, the object will float when placed in water. Sinking and floating depend on the liquid.

5. Common Densities Solids Aluminum 2.7 Copper 9.0 Gold 19.3 Iron 7.8 Lead 11.3 Platinum 21.4 Ice at 0˚C 0.92 Liquids Water at 72˚F 1.0 Water at 36˚F 0.99 Gasoline 0.7 Mercury 13.6 Milk 1.03 Gasses Air 0.001293 Carbon Dioxide 0.001197 Hydrogen 0.00009 Helium 0.000178 Nitrogen 0.001251