9th Grade Science

Chapter 1A-B

Goals

• Identify the steps scientists use to solve problems

• Define and understand the use of variables

Scientific Method

• Basic Steps:– Formulate a question– Collect information– Make an hypothesis– Test the hypothesis– Draw a conclusion (about the hypothesis)– Report!

• Why do we use it?• Song

Testing!• All science is testable!• Test may be:

– More observation– Experiment with control

• Control: a group that does not have the experimental factor changed

• Variables measured:– Independent variable:

• One thing we change!– Dependent variable:

• What we measure: what changes as a result of the independent variable

• Repeated testing leads to theories and laws

Theories and Laws• Scientific Theory:

– Explains how or why a natural event occurs– Usually incorporates many supported

hypotheses and is developed to explain them– Example:

• Scientific Law:– Describes something that occurs naturally and

seems to occur in the same way all the time– Does NOT explain how/why– Example:

Goals

• Name and define common prefixes used in the metric system

• Identify SI units for length, volume, mass, time and temperature

• Convert from one SI unit to another

How do we measure?• Metric system standard measurements

– AKA System Internationale (SI)• Length:

– Meter • Mass:

– Gram• Temperature:

– Celsius degree• Time:

– Second• Volume:

– Liter

Conversion!

• Mr. Boal’s Handy Dandy Conversion Line!

Conversion Examples

• You have a length of rope that measures 3075 mm. How long is it in:– Centimeters– Meters– Kilometers

• Your pencil has a mass of 7.5 g. What is its mass in:– Kilograms– Centigrams

• Practice Problem p 16! Your pencil is 11 cm long. How long is it in mm?

• Convert 15.6 mL to L

• Convert 25.4 kg to mg

• Volume of a solid

• Density:– Amount of mass per volume