Variables
What is an independent variable?
An independent variable is what the scientist directly changes or the cause of an experiment.
Identify the constants:
Ms. Francoeur wants to find out how the amount of water given to her plants affects the plant's height. She gave each plant the exact amount of sunlight and the same type of soil.
Amount of sunlight, type of soil
Name one cool thing that you have learned in science so far this year!
Answers will vary.
What are the 3 states of matter?
Solid, Liquid, Gas
Liquid --> solid
Freezing
What is a dependent variable?
The effect of the experiment. What the scientist measures that depends on the IV in an experiment.
A student wanted to do an experiment to find out how increasing the speed of a car affects how much gasoline is used. What is the dependent variable in this experiment?
How much gasoline is used
What is a hypothesis?
An educated guess/ prediction we make about our experiment.
(Must be written in the format: If... then... because)
What state of matter has the most tightly packed particles?
What is the phase change called when liquid turns into gas?
Vaporization or evaporation
List at least 3 key words that might tell you have a constant variable.
Same, exact, each, all
Ms. Francoeur is testing how the number of players in a game of Among Us affects how much time the game takes. What is the independent variable?
The number of players in a game of Among Us
Name the tool and unit that we use to measure volume.
Tool= graduated cylinder
Unit= liters
Why does liquid water take the shape of a cup it is poured into, but solid ice cubes do not?
Because liquids have an indefinite shape but solids have a definite shape.
When a liquid changes into a gas, is the amount of energy increasing or decreasing?
Increasing (the particles speed up and spread apart).
Scientific question: How does the shape of an ice cream cone affect how quickly the ice cream will melt?
What is the independent variable?
IV= the shape of an ice cream cone
reate a scientific question based on the following experiment:
Experiment: Ms. Francoeur and Ms. Liv want to figure out how the amount of coffee they drink affects the number of students who turn in their homework.
Must be in this format-"How does ___ affect ____?"
How does the amount of coffee affect the number of students who turn in homework?
Name the tool and unit we use to measure length.
Tool= ruler
Unit= meters
Make the three hand gestures for solid, liquid, and gas.
Must mime all three correctly with their hands.
Solid-two closed fists vibrating
Liquid-two closed fists brushing past each other
Gas-crazy fists
A cool can of soda was set on a table on a hot summer day. A student observed water vapor in the air forming water droplets on the outside of the soda can. What phase change occurred? What happened to the energy as it went from water vapor to water droplets?
Condensation, because gas cooled into a liquid. Energy decreased.
Try to come up with your own experiment, then tell me the IV, DV, and Constants!
Answers will vary.
Write a hypothesis (in the correct format!) for the following question:
How does the number of hours students spend studying affect their scores on the IA?
IF students increase the number of hours they spend studying
THEN their IA scores will also increase
BECAUSE they will be prepared
What about the particles changes during a phase change?
Their movement and distance (NOT the size, shape, or color)
Rank solid, liquid, and gas by their amount of energy (most to least).
1. Gas
2. Liquid
3. Solid
Going from a liquid to a solid, are you adding or removing energy? (Think heat.)
Explain.
Removing energy. Because the particles in a solid are closer together in a solid than they are in a liquid, you need to get the particles to slow down and get closer together.
You would remove heat because:
Adding heat: particles speed up and spread apart
Removing heat: particles slow and and get closer together