Diet Coke and Mentos

Scientific Method 3 Minutes Do Now: In the top left of your notebook… What is the difference between a dependent variable and an independent variable? Objective: In the top right of your notebook… I can apply the scientific method when conducting laboratory exercises

Portfolio Review Unit 1 – Scientific Method 9 objectives 27 pieces of evidence total Folders!

Diet Coke and Mentos Lab The purpose of this lab is to Help you practice using the scientific method Teach you expectations for lab reports in chemistry Ensure that you understand all of the vocabulary that we use with the scientific method

Diet Coke and Mentos Lab http://video. google. com/videoplay

Think Pair Share What do you think might cause the reaction between Mentos and Diet Coke?

Mmm… Diet Coke and Mentos… the best combo  Step 1: Problem (what is the question?) Step 2: Research (do you already know something about this experiment)

Observations are what we see, smell, taste, hear, or feel. Before we create a hypothesis, let’s make some observations and inferences… Observations are what we see, smell, taste, hear, or feel. Qualitative: Ex: red, blue, small, big, hot, cold, etc. Quantitative: Involves a number Inferences are a guess based on what you observe. Inference:

What kind of data is this? Class Poll Ellen counts how many breakfast sandwiches are eaten in each 1st Period What kind of data is this? Qualitative? Quantitative?

Step 3: Hypothesis – ÏF…..THEN…. What do you think is going to happen to the diet coke? Step 4: Identify your variables  What are we changing in the experiment?  What are we observing in the experiment?  What are we keeping the same? Independent Variable (what we changed) Dependent Variable (what we observed)   Control Variables (what we kept the same)   

Independent and Dependent Variables Independent Variable: The variable that you CHANGE Dependent Variable: The variable that you observe and measure the RESULT of

Example-Rain and Zebras Observation: A scientist studied the relationship between the amount of rain and the number of zebras born each spring. Independent Variable: ? Dependent Variable:

Control Variable Also called a constant Control variable: a variable which does not change during an experiment so that results remain accurate

DO NOW OBJECTIVE Experimental Group A botanist wants to determine what color ultraviolet light, if any, will result in the most optimal plant growth. He exposes plants to red, blue, and yellow ultraviolet light and compares their growth to the growth of plants exposed to the normal white light. Experimental Group I can apply the scientific method when conducting laboratory exercises Write a hypothesis that relates to this experiment. Identify the following variables: Independent Variable Dependent Variable Control Group

Experimental Group & Control Group Experimental group: the subject(s) being tested Control group: the subject(s) who do not receive experimental treatment and are used as a comparison

Don’t confuse control variable with control group. CHALLENGE: Pitfall! Don’t confuse control variable with control group. Control variables, or constants, stay the same for the entire experiment Control group is a group that is used for comparison

Example Question: Is there a relationship between the number of hours spent studying and the score a student gets on the weekly quiz? Define the: Independent Variable Dependent Variable Control Variables Experimental Group Control Group

Example 2 Independent Variable Number of hours spent studying Dependent Variable Score on the weekly quiz Control Variables Amount of sleep Content knowledge Difficulty of the quizzes

Example 2 Experimental Group Students studying more (or less) hours than normal Control Group Students studying the normal amount of hours

Graphing Data After collecting data, you need to make graphs in order to interpret the result DRY MIX Dependent Responsive Variable Y-Axis Manipulate Independent Variable X-Axis

Diet Coke and Mentos Lab  Timeline Thursday Get into lab groups Identify the ‘control’ group in the experiment Control Group = what you compare the experiment to

Control Group  Diet Coke and Mentos 2-liter bottle of Diet Coke at room temperature ‘Mentos dispenser’ to get the Mentos into the Diet Coke  Make sure you ask Ms. B what this will look like!!! 3 mint Mentos

Determine what independent variable you want to manipulate in your experiment (5 minutes!!!!!) Write out your group’s plan (Thursday/Friday) Get your plan approved by Ms. Bergman (Friday) Buy supplies (by Monday!!!)

What do you need to know? Control Independent variable Dependent variable(s) Materials needed Lab report format

Lab Write Up Format Title Purpose Hypothesis Materials Procedure Scientific Method Lab Write Up Format Title Purpose Hypothesis Materials Procedure Data Collection Analysis (answer questions) Conclusion

Scientific Method Rewrite in your own words

Crossword puzzle (Due Friday) Work on Diet Coke and Mentos Lab Homework Crossword puzzle (Due Friday) Work on Diet Coke and Mentos Lab What is your procedure? Do you need to get any supplies?