Density is a way to measure how tightly packed an object is. Denser objects have less empty space in them, they are less holey.The density of an object is often measured in grams per milliliter.
The density of an object is often measured in grams per milliliter. So to measure the density of an object you would put it on a balance to measure how many grams it is (the object's mass) then divide that number by the amount of space the object takes up (its volume).
The density of an object compared to the density of water tells us whether the object will float or not. The density of water is about 1.00 g/mL. If the density of an object is less than the 1.00 g/mL, the object will float in water. If the density of something is greater than 1.00 g/mL it will sink in water.