A 1 mL sample weighs 4 g, the density of the sample is

Ok so density is mass volume

D=m/v

mass in this case is 4 g
volume is either mL or cm^3 and in this case its 1 mL so

D=4 g/1 mL
D=4 g/mL

Ithink this is what you meant. the temperature at which a liquid begins to boil is called the boiling point. the boiling point of water is 212°f or 100°c.  and at that point will start to turn into steam (gas)