1. Today is Thursday, February 21, 2013
Homework:
- START YOUR EXPERIMENTS
- Read Chapter 11, Lesson 3 (for tomorrow)
- Ch. 11 H.W. Packet (due Monday)
- Determine the following and turn in for tomorrow:
- In your Science Fair Experiment, what is….
- The independent variable, dependent variable, experimental group, and control group?
- Turn this in for a grade tomorrow
Science Fair Materials So Far compilation project (DUE Friday, Feb. 22 – TOMORROW)
Warm UP:
Please complete the pop quiz quietly. You may use your textbook (Chapter 11) and your notebooks (notes from yesterday). PLEASE DO NOT TALK.
Glue notesheet into science notebook

2. Goal for Today
SWBAT Understand how to determine the physical properties of materials such as their weight, mass, volume, density, and buoyancy. SWBAT Identify the dependent and controlled variables in an investigation.

3. Some review from yesterday….
Elements are basic building blocks of matter.
Can’t be broken in smaller pieces with ordinary physical or chemical processes
Few found in nature in pure form (i.e. gold)
Elements combine to form things around us
Rust = iron and oxygen
Living and non-living things made up of a few elements combined in many ways
Elements have chemical and physical properties. Use properties to identify them

4. New Material…. Physical and Chemical Properties
Chemical properties – the atomic composition of a material; can help us know how a material changes into other materials
Physical properties – can be measured without changing the material. Examples mass, volume, color, odor, and phase at room temperature
Property of objects – properties only true for the object you’re looking at
Property of material – properties that are the same no matter how you bend, cut or crush the object (i.e. density, color, hardness, texture, magnetism)

5. Weight and Mass
Weight (N) – a measure of the pull of gravity on an object.
Measured with a spring scale. Spring is pulled or squeezed
Standard international unit in science is the Newton (N)
Weight changes with changes in gravity
Mass (kg) – the amount of matter in an object
Measured with a balance
Standard international unit in science is the kilogram (kg) – NOT THE GRAM, unusual, but true!
Doesn’t change with location

6. Volume (m3) – the amount of space an object takes up.
Different ways to find volume.
Standard international unit in science is the cubic meter (m3)
Measure using a ruler. Length x width x height
Or placing object in water and looking at water displaced. Good method for irregular objects.

7. Density = mass/volume (draw a broken heart to help remember)
Density – a measure of the amount of matter in a given volume; another physical property of material
Same for a substance no matter how much of it is measured
Density = mass/volume (draw a broken heart to help remember)
Buoyancy – tendency of an
object to float.

8. Experimental Design What are the components of a good experiment?
Independent Variable – The variable in an experiment that you control.
- Dependent Variable – The variable in an experiment that depends on your independent variable.
- Control Group – The group in the experiment exposed to “standard” conditions – no independent variable applied to this group!
- Experimental Group – The group in the experiment exposed to experimental conditions – your independent variable is applied to this group.

9. Closing it up…. What is density? Mass/Volume (Mass per unit of volume)
What is an independent variable in an experiment?
The variable that you are testing. YOU control this variable.