Today Hand in work Check the list in the back, if you owe something. Get out a half sheet of paper, PUT YOUR NAME ON IT, share the other half. When bell rings the quiz will start and you will have 1 minute per question to answer.

Question 1 What 3 elements makes up the troposphere? (use your ESRT)

Question 2 What layer of the atmosphere has most of the water in it?

Question 3 What is the temperature at the Tropopause?

Question 4 What happens to pressure as you increase altitude?

Answers 1.) Oxygen (21%), Nitrogen (78%) other (1%) 2.) Troposphere 3.) -55oC 4.)Pressure decreases when altitude is increased. 10 points off for each incorrect answer! 100- points = the grade.

Vocab Density Mass Volume Graduated Cylinder Scale or triple beam balance

Density The first really important idea!!! (coke and diet coke?)

Why is density important? Earth Science is the study of the planet. Ask yourself this: Is there a lot of oil to use on this planet? How do we get it out of the ground? Should I dump chemicals into the water we use to drink? How do the chemicals mix? How to I clean up these messes, if they are every made? – How do you clean up if you spill oil? How does weather interact with the earths crust?

Density What is the formula for Density? (Yes you do know) What is your Mass? – How much stuff makes you. What is you Volume? – How much of you there is. So your Density is the amount of Mass divided by the Volume you take up – It is how tightly pack the molecules are in a space! M D * V

Cool info (layers) Air = g.mL Liquid Water (4oC) = 1.0 g/mL Ice = 0.9 g/mL Iron = 7.9g/mL People= 1.0 g/mL Plastics = vary form Earth = 5.5 g/mL Saturn (yes the planet)= 0.7 g/mL Black hole 400,000,000,000,000 g/mL

Icebergs (dead ahead) If ice floats (less dense than water) where is most of the ice then? Only 10% of the whole berg is above water level why?

Does density change? The question is does density change? – I start with a block of wood and cut it. – What do I have then? – Density doesn’t change with size!! – Same thing with rocks, minerals counties and people. » If I cut you arm off your mass and volume would be lower equally, so your density would be the same! Let’s try it!

Can I change Density? (yes) Heat – By adding heat I change the energy level of matter causing the volume to change. Pressure – By squeezing an object the volume is changing. Think about it! – If I heat a rock up till it melts what happens? – If I squeeze a rock what happens?

Calculating and measuring Density is mass over volume How do I measure Volume? – L*W*H (cm3) – Graduated Cylinder (mL) How do I measure Mass? – Scale (g) or triple beam balance So if D=m/v what are the correct units for density? M D * V

Relate density to weather Warm air does what compared to cold air, because it is less dense? Object usually do what when they freeze? – Heat up?

Practice Find the density if the mass is 10 g and the volume is 1 mL? – Formula? – Answer? Find the volume if the mass is 20 g and the density is 10 g/mL? – Formula? – Answer? Find the mass if the density is 5 g/mL and the volume is 10 mL? – Formula? – Answer?