A student is give a liquid sample to identify. He performs the following measurements to do the identification:
a. he weighs a flask and stopper (mass = 65.590g)
b. he adds eactly 10.00 ml of the unknown liquid to the flask and stoppers it again.
c. he weighs the flask and stopper and liquid (mass = 74.78 g)

Calculate the density to the correct number of sig figs. What is the liquid?

density = mass /volume
mass of the liquid = 74.78 g-65.590g= 9.19g
volume = 10.00ml
density = 9.19/ 10 .00=  0.919 g/ml
now check from the table with substances and densities and identify the element.