Density

Do Now: Describe the objects on the desk. Infer what you think will happen when the Coke can is placed in the water? Infer what you think will happen when the Cherry Coke Zero can is placed in the water? Infer what you think will happen when the Diet Root Beer can is placed in the water? What actually happened?  What do you think is responsible for the outcome you observed?

Coke Diet Coke

What is density? Take a look at the two boxes below. Each box has the same volume. If each sphere has the same mass, which box would weigh more? Why? The box that has more spheres has more mass per unit of volume. This property of matter is called density. The density of a material helps to distinguish it from other materials.

Density is a comparison of how much matter there is in a certain amount of space. It is a measure of how tightly packed the molecules are in a substance. Which square is more dense? (in other words, which is more tightly packed?)

Now which one is more dense? Density depends on how much matter there is AND how much space there is. Density depends on mass and volume.

Remembering Mass & Volume What is mass? The amount of matter in an object. What is volume? The amount of space an object takes up.

So basically density is… How much matter is crammed into a certain amount of space! That’s a dense crowd!

So what would be more dense? An object that has a large volume and a small mass An object that has a small volume and a large mass OR

Density & Phases of Matter So which is more dense: a solid, liquid or gas? Usually, solids are the most dense & gases are the least. Solid Liquid Gas

Floating & Sinking When putting an object in water, objects less dense then water will float. Example, cork floats in water. When putting an object in water, objects more dense then water will sink. Example, rocks sink in water.

Density