Show:
PHYSICAL & CHEMICAL CHANGES
Variables
Matter and Measurement
Experiments
More experiments
100
If a bike left outside in the rain makes the bike rusty, is it a physical change or chemical change and why?
Rust is a chemical change because the bike cannot be changed back to not being rusty.
100
What is the other way you can say "change variable"?
Independent variable.
100
Explain what matter is AND name the three states of matter.
Matter is anything that has mass and takes up space. The 3 states of matter are solid, liquid, and gas.
100
What were the different types of dairy in the ice cream experiment?
cream, whole milk, yoghurt
100
What was Adryan and Kayden's question?
What side of the gym is better to shoot a basketball from?
200
When water freezes to make ice. Is this a physical or chemical change? Explain your answer.
It is a physical change because the water is changing its state of matter; it is changing from a liquid to a solid.
200
What is the dependent variable? Give an example.
The variable you are measuring. It is dependent on the independant variable.
200
What are the two ways that we measure matter? Think "Q"
Qualitatively and Quantitatively.
200
On the cleaning coins experiment, which liquid worked the worst?
Baking soda and water
200
What material did the best job of protecting Drew's water balloon? What did he say he would do differently if he did the experiment again?
Bubble wrap Use eggs, as they break easier. Drop from different heights.
300
I took a piece of paper and rolled it up into a ball. Is this a physical change or chemical change. Explain your answer.
It is a physical change because a new substance is not formed. It is just changing its shape. There is no new odor, color or other reaction that occurred.
300
What is the control variable? Give an example.
The variable that you do nothing to, so that you can compare your results.
300
What tools did we use in the lab to measure matter quantitatively? What were we measuring?
Mass - triple beam balance scale Volume - beakers, cylinders
300
What does a barometer measure?
air pressure
300
In the fruit battery experiment, was the hypothesis correct? Why or why not?
The hypothesis was that the lime would work best. All the fruit worked, but they could not determine which worked best as the voltmeter was not accurate enough.
400
What are three examples of chemical change properties?
-Odor -New color -Creates bubbling -A new substance is formed
400
Krusty Krabs Breath Mints Mr. Krabs created a secret ingredient for a breath mint that he thinks will “cure” the bad breath people get from eating crabby patties at the Krusty Krab. He asked 100 customers with a history of bad breath to try his new breath mint. He had fifty customers (Group A) eat a breath mint after they finished eating a crabby patty. The other fifty (Group B) also received a breath mint after they finished the sandwich, however, it was just a regular breath mint and did not have the secret ingredient. Both groups were told that they were getting the breath mint that would cure their bad breath. Two hours after eating the crabby patties, thirty customers in Group A and ten customers in Group B reported having better breath than they normally had after eating crabby patties. 1. Which people are in the control group? 2. What is the independent variable? 3. What is the dependent variable? 4. What should Mr. Krabs’ conclusion be?
1. Which people are in the control group? The people who received the mint without the secret ingredient (Group B) would be the control group. 2. What is the independent variable? Secret ingredient in the breath mint 3. What is the dependent variable? Amount of breath odor (or bad breath) 4. What should Mr. Krabs’ conclusion be? The breath mint with the secret ingredient appears to reduce the amount of breath odor more than half the time, but it is not 100% effective.
400
Describe the relationship between a liquid and a solid. This means, what happens when a liquid turns into a solid and when a solid turns into a liquid? (Be careful! This requires TWO answers).
When a liquid turns into a solid it is freezing, when a solid turns into a liquid it is melting.
400
In the"Do plants need water?" experiment, what was the hypothesis? Was it rejected or accepted?
They hypothesis was that pop would be the best for growing plants because of the sugar. This was rejected, coffee was best.
400
In the mint candy experiment, who remembered the most, and who were "outliers", and did not do better after having a mint?
Keara - 16 Amelie and Jay remembered the same or less
500
Is lighting a match a physical or chemical change? Explain your answer.
Lighting a match is a chemical change because there is a new odor, a change of color, and the burnt match cannot be changed back.
500
SpongeBob Clean Pants SpongeBob noticed that his favorite pants were not as clean as they used to be. His friend Sandy told him that he should try using Clean-O detergent, a new brand of laundry soap she found at Sail-Mart. SpongeBob made sure to wash one pair of pants in plain water and another pair in water with the Clean-O detergent. After washing both pairs of pants a total of three times, the pants washed in the Clean-O detergent did not appear to be any cleaner than the pants washed in plain water. 1. What was the problem SpongeBob wanted to investigate? 2. What is the independent variable? 3. What is the dependent variable? 4. What should Sponge Bob’s conclusion be?
1. What was the problem? SpongeBob’s pants were not clean. 2. What is the independent variable? Laundry soap 3. What is the dependent variable? Amount of dirt left on the pants (or how clean the pants were) 4. What should Sponge Bob’s conclusion be? Clean-O laundry soap does not appear to be effective in cleaning his pants.
500
How do you measure the volume of an irregularly shaped object, like a piece of gold?
Using displacement. Place the gold in a beaker of water. The amount of water displaced (the amount the volume increases), is the same as the volume of gold. Archimedes principal!
500
What is osmosis? (Think salty water, pure water, and vegetables!)
The movement of water across a membrane from a high concentration to a low concentration.
500
List all the steps in the scientific method, including the most important aspect of each step. You should have 6.
1.identify a problem or a question 2. state your hypothesis 3. outline your procedure (detailed enough so that otherscan do it) 4. do the experiment, collect data and observations 5. conclusion - accept or reject hypothesis 6. communicate results!