WARM UP: October 8 th, 2013 Calculations with Significant Figures Solve and Report with the Correct Number of significant figures. Be sure to include units. Look at the operation and use the correct rule! 1.12 mL mL = 3.40 g / 21.2 mL =

WARM UP: October 8 th, 2013 Calculations with Significant Figures Solve and Report with the Correct Number of significant figures. Be sure to include units. Look at the operation and use the correct rule! 1.12 mL mL = =13.43 mL 3.40 g / 21.2 mL = = g/mL

Agenda Check Workbook Page #13 Set up Lab Notebook Lecture on Density Collect Data for Density Lab Begin/Complete Lab Report Homework: Workbook p (Significant Figures with Density)

Mini Lesson Unit 2 Density

Sink and Float Challenge I have a copper penny weighing 4 grams and a block of wood 130 grams. Predict if either will float in the water.

What will happen? 1.Both will sink. 2.Both will float 3.Penny will sink and wood will float 4.Penny will float and wood will sink WHY?

What happened? Density of Wood 0.40 g/mL Density of Water is 1.0 g/mL Density of Copper is 8.9 g/mL Items that are less dense float in water. Items that are more dense sink in water. Floating and Sinking Behavior Has to do with Density not Weight!

Definition of Density D = mass/ volume Mass is usually measured in grams Volume is measured in mL for liquids Volume is often measured in cm 3 for solids Remember 1 mL = 1 cm 3 (add this to your notes!)

Which is a Unit of Volume? 1.Grams 2.Meters 3.Milliliters 4.Centimeters

25 cm 3 equals 1.25 meters mL 3.25,000 mL 4.25 mL

Every Element or Compound has a Unique Density Density is an intensive physical property (not dependent on amount) that can identify a pure substance. elements/density.htm

Density Triangle Density = M/V V M D If the volume is 2.0 ml and it weighs 4.6 grams what is the density of the Substance? 2.3 g/ml

Density Triangle Density = M/V V M D If the density is 4.0 g/ml and it has volume of 1.5 mL what is the mass of the substance? 6.0 g

Density Triangle Density = M/V V M D If the mass is 4.5 g and it has a density of 1.5 g/mL what is the volume? 3.0 mL

M = 25 g V = 50 mL What is Density? g/mL g/mL g/mL g/mL

D = 3.0 g/mL M = 4.5 g What is the volume? mL mL mL mL

How do you find density of a liquid? 1.Measure the volume using a graduated cylinder. 2.Measure the mass on a scale. 3.Divide the mass by the volume 4.The unit of density is usually g/ml

How do you find the density of a solid?

The initial volume of a graduated cylinder is 11.5 mL. A solid object is dropped in and the water level rises to 14.0 mL. What is the volume of the solid object? 1.14 mL mL mL mL

Time for Lab!!! Set up your lab notebooks following the directions in the handout. Before you begin the lab you should have the following categories already completed or all set up: Title Date Group members Purpose – you may summarize this Data Tables