A characteistic property Density A characteistic property

Who is that masked Molecule? A characteristic property is something you can use to identify an unknown Pure substance.

Density to the rescue If we know it’s density then we can determine which pure molecule it is. Density is the mass divided by the volume. D=M/V It always stays the same even if you have a lot or a little. My mass is 42.5 grams My volume is 42.5 ml My density is 42.5g/42.5 ml= 1g/ml Who am I?

Check you tables Air has a density of 0.00129g/ml Gasoline 0.69 g/ml Fresh water 1g/ml Parafifin wax 0.9 Glycerine 1.26g/ml Aluminum 2.7g/ml Iron 7.9 g/ml

Tah dah! I’m Water 1g/ml If it is more dense than water it floats If it is less dense than water it sinks. Look back at the table name 1 thing that floats and 1 thing that sinks

Phases of matter and density Mass is the amount of stuff or particles you have Volume is the amount of space it takes up Density is the amount of stuff in a space Gases are less dense Than liquids and Liquids are less dense than solids

This is one of the most important things you will learn this year Density is a characteristic property Density can identify unknown pure substances Density is Mass divided by volume D=M/V The units are g/ml for liquids and gases g/cm3 for solids