Quote: The function of education is to teach one to think intensively and to think critically. Intelligence plus character - that is the goal of true education. Martin Luther King, Jr.

Wednesday 1/23/13Objective: Understand link between percent abundance and atomic mass.

Bell• An element has three isotopes. What is the average mass for

the element?Isotope Mass (amu) Isotope Abundance (%)38.9637074 93.258139.9639992 0.011740.9618254 6.7302

Which is more abundant and why?

Boron-10 or Boron-11

Finals• Monday 1/28• 1st, 4th and 7th periods

• Tuesday 1/29• 2nd ,5th and 8th periods

• Wednesday 1/30• 3rd and 6th periods

• Periods with finals are 60 minutes long• Other classes are 42 minutes• Get out at 3:28 pm• Make-up exams Thursday during regular 50

minutes

Review: Density

What is the formula for density?How do you find slope?What are definitions for mass and volume?What are the units for mass, volume and density?

1.) Which substance, black or purple line has a larger density?

2.) 300 g of which substance occupies a greater volume?

3.) What is the density of the black line substance?

4.) 75 g of the black has what volume?

5.) What is the mass of 45cm3 of black line substance?

A cube of metal with a volume of 42.9 cm3 has a mass of 117g. How dense is the metal?

Review: Measurement

How many mL in the cylinder and how many cm does the arrow show?

Review: Observation• Make a qualitative observation about the picture• Make a quantitative observation about the picture

Review: Chemical vs Physical

Mark the following as chemical or physical• Car rusting• Paint drying• Water freezes• Eating a hot dog• Baking cookies• Cutting a brownie into pieces• Acid etching glass• Dew forms on leaves

Law of Conservation of Matter• What is the law?• Draw a picture showing how dissolving salt follows the law.

Salt Water