Mass, Volume, Density: Summary & Definitions

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