What Is Everything Made of? If it has mass and volume its…

Examples of Matter.

What Is Not Matter. Energy (heat, light, electricity, etc). Forces (gravity magnetism and the nuclear forces) Space itself is a 3-D “fabric” but not matter.

Law of Conservation of Mass. Matter cannot be created nor destroyed. A burning log does not disappear, collect all the smoke and ashes and the mass is the same. Nuclear reactions can turn matter into energy E=mc 2

Mass is a Measure of the Amount of Matter Mass is measured with a triple beam balance. Mass is measured in grams (g), a gram is the mass of 1cm 3 of water and is about the mass of a paperclip 1000g = 1 kilogram (kg)

Volume Volume = measure of the amount of space a piece of matter occupies. 1 milliliter (mL) = 1cm3 mL is used for liquids, cm 3 is always right 1000mL = 1 liter (L)

Volume of Rectangular Objects Measure length, width and height in centimeters (cm) Multiply length x width x height Example: A block is 10 cm long, 2 cm wide and 3 cm tall. Its volume is 10 cm x 2 cm x 3 cm = 60 cm 3

Measuring Volume Use a graduated cylinder for liquids. Measure at the bottom of the meniscus Use an overflow can for oddly shaped objects

Measuring Measure to 2 decimal places with a ruler or triple beam balance Measure to 1 decimal place with a graduated cylinder. Last number is always a guess. When calculating, your answer can never have more decimals than your data.

What is density? Density = mass ÷ volume (d=m/v) Density is a way to compare how heavy something seems compared to it’s size.

Which one is more dense?

D = m/v Denser things sink, the bigger numbers end up on the bottom The density of pure water is 1.0 g/cm 3. Anything denser sinks; anything less dense floats. Saltwater is denser than fresh.

Density explains why: hot air balloons take off before dawn. very light sand grains sink, while very heavy aircraft carriers float. the earth has layers, volcanoes, and why land rises and sinks. how we can separate things like crude oil into its parts (gasoline, diesel, etc.).

Example: An object has a mass of g and a volume of cm 3. What is its density and will it sink or will it float in fresh water? D=m/v D= g/340.0 cm 3 D=0.6g/cm 3 (we only get to keep 1 decimal place) It will float because it’s density is less than 1.0 g/cm 3

Example 2: A graduated cylinder starts with mL of water. An object with a mass of 12.3 g is lowered into the water. The water in the cylinder goes up to mL. What is the density of the object? Volume = 56.78mL mL Volume = ml (we only get to keep 2 decimals) D= m/v D= 12.3g/11.65cm 3 D=1.1g/cm 3 D=1.1g/cm 3 (we only get to keep 1 decimal)

Liquid Layers If you pour together liquids that don’t mix and have different densities, they will form liquid layers. The liquid with the highest density will be on the bottom. The liquid with the lowest density will be on the top.

Liquid Layers Check out this picture from your book. Which layer has the highest density? Which layer has the lowest density? Imagine that the liquids have the following densities: 10g/cm 3.3g/cm 3. 10g/cm 3.3g/cm 3. 6g/cm 3.5g/cm 3. 6g/cm 3.5g/cm 3. Which number would go with which layer?

Liquid Layers – Try on your own! Imagine that the liquids on the right have the following densities: 15g/cm 3 10g/cm 3 15g/cm 3 10g/cm 3 3g/cm 3 9g/cm 3 3g/cm 3 9g/cm 3 7g/cm 3 12g/cm 3 7g/cm 3 12g/cm 3 Match the colors to the correct densities. 3g/cm 3 7g/cm 3 9g/cm 3 10g/cm 3 12g/cm 3 15g/cm 3

Density can be used to identify substances. Density can be used like a fingerprint tell elements and compounds apart. Density can be used like a fingerprint tell elements and compounds apart.

Review What is the formula for density? What happens if you pour together liquids that have different densities? Will the liquid on the top have the highest or lowest density? Will the liquid on the bottom have the highest or lowest density?