Matter has mass and volume. Mass: the amount of matter in an object. A triple beam balance is used to measure an object’s mass in grams (g).

Weight vs. Mass: -weight is a measure of gravitational pull on an object. -Mass is the amount of stuff (matter) in an object.

Volume: the amount of space an object takes up Volume: the amount of space an object takes up. How can you prove that a solid object takes up space? A graduated cylinder can be used to measure a small object’s volume in milliliters (ml).

-A bowling ball and a volleyball take up the same amount of space -A bowling ball and a volleyball take up the same amount of space. Therefore, they would have the same what? -Which would you prefer dropping on you foot? The difference between the two objects is their individual mass. Both mass and volume can be easily measured.

Density: the amount of matter an object has compared to its size or volume. -Scientists refer to density as the mass per unit volume of a substance. In other words, density is how tightly packed the atoms are in an object. If you compare the volleyball and bowling ball which is more dense?

-Let’s compare two objects of equal size, a block of wood and a block of copper: Both the objects have the same volume (size). The matter (particles) that make up the wood are farther apart than the particles of matter that make up the copper. The matter in the copper is more compacted than the matter in the wood. The farther apart the particles, the less dense the substance.

-Here’s another example: If you have two trashcans of equal volume and you place the same amount of garbage in both cans, then you could say the density of trash can A and B are the same. -What if you climb in trashcan B and jump up and down on top of the trash compressing the trash or matter into the bottom of the can? You can climb out, put more trash in the can, and repeat this task until you cannot put anymore trash in can B. Which is more dense now?

-Therefore density can also be expressed as g/cm3. -Since the mass of an object can be expressed in grams and the volume in milliliters we can express density as grams per milliliter (g/ml). -However, we can sometimes find volume with a ruler (l x w x h), and one milliliter is equal to one cubic centimeter (cm3). 1 cm = 1 milliliter (ml) 1 cm 1 cm -Therefore density can also be expressed as g/cm3. -By standardizing measurements of density, we can compare the densities of different substances.