In this first video we have a good summary of the general properties of mass and volume and the specific property of density, which is derived from them.
Don’t worry too much about the numbers and the fractions, its easy to understand by the images alone. The formula is the one we learnd in class:
Density = Mass / Volume
In this second video you can revise what we learned about which objects sink or float. Objects with a density higher than water’s (1g/cm3) sink, and those with lower density float.