Do Now Pick up a note packet (front desk) Place HW on your desk to be checked Work on equipment practice (last page of yesterday’s packet) 1st Quiz: Lab Safety & Equipment MON 1/25

Safety Equipment Locations FRONT DOOR

A Note About the Safety Shower It is truly there for EMERGENCIES ONLY. NO ONE should have to pull the safety shower in this class. Ever.

Can’t really be modified… Science refers to a system of acquiring knowledge. This system uses observation and experimentation to describe and explain natural phenomena. EXPLAINS DESCRIBES/ STATES mathematical formula Can be modified/disproven Can’t really be modified… Ex: Kinetic Molecular Theory --explains the behavior of gas molecules Ex: Boyle’s Law--States the relationship between gas volume and gas pressure

Theory vs. Law cont. **A theory DOES NOT become a law!** Both are supported by LOTS of evidence Both can be used to predict outcomes Both are widely accepted by the vast majority of scientists **A theory DOES NOT become a law!**

A Scientific Method What is the “scientific method”? It is a process that is used to find answers to questions about the world around us. Note that there is not one “scientific method”   What is a hypothesis? It is an educated guess based on observations and your knowledge of the topic. What is data? It is information gathered during an experiment.

Identify the problem Form a Hypothesis Create an Experiment Perform an Experiment Analyze the Data Modify the Experiment Communicate the Results

Variables in Scientific Experimentation Independent Variable=the variable that _ (the scientist) __________________________ When graphing, this appears on the _____________ Dependent Variable=the variable that _____________ due to the _______________ It is what you are measuring When graphing, this appears on the ______ I have control over in an experiment x-axis changes/responds independent variable y-axis

Example Let’s say we want to know if other sodas will react with Mentos like Diet Coke does. We test a bunch of different sodas with mentos and measured how long each one fizzed. My two variables are type of soda and fizzing time. What’s the Independent Variable? What’s the Dependent Variable?

Variables in Scientific Experimentation Constants=variables that are kept the same throughout the experiment Control Group= the original experiment without any changes; It’s the group you’re comparing to.

Think back to the soda and mentos example What are some things we could hold constant in this kind of experiment? What setup could serve as the “control” group, the one we compare all the results to?

Patterns in Data: When appropriate, data can be plotted as a scatterplot and a trend (pattern or relationship) may be observed between the two variables Direct Relationship=as one variable increases, the other variable also increases

Inverse Relationship= as one variable increases, the other variable decreases

What was Mr. Krabs’ hypothesis? What is the independent variable? What is the dependent variable?

Which people are in the control group? Were there any variables that were held constant for both groups?

What should Mr. Krabs’ conclusion be? Why do you think 8 people in group B reported feeling better? Placebo effect (you feel better because you think you’re getting the real stuff…)

What was Patrick’s hypothesis? What is the independent variable? What is the dependent variable? Which fish are in the control group? Were there any constants for this experiment?

Look at the results in the charts. What should Patrick’s conclusion be? How many fish in the special food group swam faster (had a lower “after” time?) How many fish in the regular food group swam faster (had a lower “after” time?)

Units *Unit= any standard that is used for comparison in numbers or measurement Whenever you report a measurement, you report a number followed by the unit

System International (SI) Units: an international system of measurement based on the metric system. Some common ones we’ll be working with are: Measurement Base Unit Symbol Length meter   Mass gram Volume Liter Temperature Kelvin Energy Joule Frequency Hertz Pressure Pascal Amount of Substance Mole Density grams/milliliter or grams/centimeter3 m g L K J Hz Pa mol g/mL or g/cm3

Prefixes: placed before the base unit to indicate a larger or smaller quantity; based on powers of 10.

x1000 x10 x10 x10 x10 x10 x10 x1000 x1000 Prefixes at the top of the chart represent a larger amount or quantity. Prefixes at the bottom of the chart represent a smaller amount or quantity.