Observations and Variables
Observations
In todays lesson you will be practicing making observations. I will do
three demonstrations for you and you will record your observations in
this worksheet.
Demonstration #1 - Flame Test
What can we observe?
Record your observations into the table below.
Table 1 - Flame test observations.
Chemical
Observations
Ba (Barium)
K
(Potassium)
Na (Sodium)
Li (Lithium)
Cu (Copper)
Ca
(Calcium)
Sr
(Strontium)
Tell me in the table below what you are still wondering about (what questions or predictions do
you have about the object or event?)
Table 2 - What I am still wondering.
Demonstration #2 - Balloon Rocket
Beginning to think about variables.
In this demonstration I want you to think about things we
could measure and observe as well as things we could
change.
Table 3 - What could I measure or observe about the balloon on the string? (Possible
dependent variables)
Share one thing from Table 3 on padlet. Link will be provided in the Zoom chat.
Table 4 - What could I change or cary about the object or event that may affect what I could
measure or observe? (Independent and Control Variables)
Demonstration #3 - Flaming Bottle
After watching me demonstrate the flaming bottle I want
you to record everything you observed below in the box.
Table 5 - Observations of flaming bottle.
There are two types of observations that can be made.
Using the image above to help you organize your observations from Table 1 into the two
different categories below.
Table 6 - Observations from table 5 organized.
Quantitative Data
What things could you record.
Qualitative Data
Wondering
Tell me in the table below what you are still wondering about (what questions or predictions do
you have about the object or event?)
Table 7 - What I am still wondering.
Variables (demonstration #3)
You have already practiced organizing variables in demonstration #2. You will do the same for
demonstration #3.
Table 8 - Organizing variables.
Choose 1 thing you would
change
(independent variable)
Things I could
measure/observe
(dependent variable)
Things I could keep the same
(control variable)
Practice
Directions: Identify the dependent (DV) and independent variables (IV) in the scenarios below.
Example: Mr. Jones wants to grow sunflowers. Every other day he gives 1 liter of water to the
plants in his front yard, and 3 liters of water to the plants in his backyard. After one month the plants in
his front yard have grown to 1 foot tall, and the plants in his back yard have grown to 3 feet tall.
DV: height of sunflower plants
IV: amount of water given to plants
1) Ryan loves playing video games, even on school nights when he should be studying! On Sunday
night he went to bed at 9:30 pm, and the next day he felt great and aced all of his assignments at
school. On Tuesday night he stayed up playing video games until 3 am, and he was so tired the
next day he couldn’t finish any of his classwork.
DV:
His performance at school
IV:
The time that he went to bed.
2) Ms. D collects all of her used bottles and aluminum cans, both at home and at school. Every
month she takes the items to the recycling truck to turn them in for money. In October she took
in 3 full bags and earned $9.75. In November she took in 1 bag and only earned $2.89.
DV:
IV:
3) Lacey works at a dress shop specializing in wedding gowns. During the month of May she had
400 appointments, sold 200 dresses, and earned $4000 in commission. However, during the
month of November, she only had 70 appointments, sold 25 dresses, and earned $1000 in
commission.
DV:
IV:
4) Austin wants to see if drinking Monster will make him a better soccer player. For Monday’s
game he drank 2 cans of Monster and scored 4 amazing goals. For Thursday’s game he only
drank water, and he scored 1 goal.
DV:
IV:
5) Mr. Morales wants to know if wearing a special cologne will get him more dates with the
ladies. On Friday night he sprayed on some expensive Aqua di Gio and talked to 8 girls at
Level 4. The next weekend he sprayed on some cheap Axe, went to Level 4 and talked to 2
girls, one of whom pretended not to speak English.
DV:
IV:
Resources
https://www.youtube.com/watch?v=l0jTMDtX4WY Mythbusters Variables