Mass:  mass is the amount of material in an object.  Mass is measured with a balance, usually in grams or kilograms.

Volume: volume is the amount of space occupied by an object. Volume is measured using a graduated cylinder or  is determined by calculation using the dimensions of the object.   Volume is measured  in  cm3, m3, mL and L.

Block

If the object is a square or rectangular block, use the formula   V = L x W x H to calculate volume.

Cylinder

If the object is cylindrical, use formula on the right to calculate volume. Liquid

If the substance is a liquid, just measure its volume with a graduated cylinder

For irregular-shaped objects:

Use the method known as displacement.  Fill a graduated cylinder or a container with a scale with a set amount of water.  Record the reading ( ie 50 mL).  Carefully add the irregular-shaped object to the cylinder.  Record the new reading ( ie 53 mL) and subtract that from the reading of the water only. The volume of the irregular-shaped object must be 3 mL.

Density:  Density is a mass to volume ratio. Density can be used to identify a substance because every pure substance has a unique density value. Objects with smaller densities will float in liquids that have greater densities.

Calculating Density:  Use the following formula:

## Density Chart for Common Substances

 SUBSTANCE STATEAT20C DENSITYAT20C( g/cm3) gold solid 19.32 Lead solid 11.35 silver solid 10.5 copper solid 8.93 nickel solid 8.9 iron solid 7.88 aluminium solid 2.7 glass solid 2.7 rubber solid 1.2 oak(wood) solid 0.7 -0.9 pine(wood) solid 0.4 -0.5 Styrofoam solid 0.005 mercury liquid 13.6 glycerine liquid 1. 26 Sea water liquid 1.01 water liquid 1 acetone liquid 0.791 Methyl alcohol liquid 0.71 Ethyl alcohol liquid 0.79 chlorine gas 0.0032 Carbon dioxide gas 0.002 air gas 0.0013 ammonia gas 0.0003 helium gas 0.0002 hydrogen gas 0.0001 