Parts of an Experiment
This is completed before an experiment takes place. A guiding question written in a cause and effect statement (if...then...)
A hypothesis
Definition of weight
A measure of the force of gravity acting on an object.
True or false:
A law describes why a natural phenomenon occurs in nature
False
Replication or repetition:
Sarah is following another student’s written procedures for an experiment that was already performed.
Replication
The ability to conduct an electric current, dissolve in water and melt are ________
Physical Properties
This is the group we compare our test trials to. This is not exposed to the independent variable.
a control group
Definition of Mass
Amount of matter that makes up an object.
True or False:
A theory can be proven or disproven with one experiment or new finding.
False
Repetition or replecation:
Joseph conducts his own experiment 25 times.
Repetition
For a lab activity in class, a student is given a mixture of small pieces of iron, sand, water, and salt. What physical property could be used to best separate the iron from the other ingredients?
Magnetism
If your results do not support your hypothesis, what would you do next?
Share results honestly
What affects weight but does not affect mass?
Gravity
Law or Theory:
An object in motion tends to stay in motion unless another force acts upon it
Law: Newtons 1st law of motion
Replication or Repetition:
Rashawn is conducting an experiment using tennis balls. He completes 30 trials and has 2 of his friends complete the experiment by following his procedures.
BOTH
flammability, toxicity, reactivity with other substances, and acidity are all examples of what?
Chemical Properties
Brandon noticed that hummingbirds in his yard visited all the flowers, but especially seemed to like the red trumpet-shaped ones. He read that they use the nectar in the flowers for food. He assumed that since the parents were eating nectar, they must feed their babies nectar as well. To his surprise, he saw hummingbirds bringing small insects and spiders to feed the young hummingbirds. How does this new evidence affect his original assumption?
He should change his original assumption that they only feed their babies nectar.
A person’s mass on the moon is 70 kg. What is true about this person’s MASS on Earth? (8.P.8.2)
stays the same / 70kg
Law or theory:
An asteroid struck earth 65 million years ago causing dinosaurs to become extinct.
Theory:
"Alvarez hypothesis"
What type of evidence are you using if you conduct an experiment and draw conclusions that relies on gathering and evaluating evidence?
Emperical evidence
Jake and Mary rolled a watermelon into the pool. The watermelon floated in the pool. What conclusion can they make?
The density of the watermelon was less than the density of the pool water.
Amy wants to test to see if the amount of fertilizer affects the growth of her rose bush. Amy uses 50 grams of fertilizer for rose bush A and 100 grams of fertilizer for rose bush B. She observes 10 rose buds blooming on rose bush B and only 7 on rose bush A.
How cans she improve her experiment design?
Add a control group - No fertilizer.
A person’s mass on the moon is 70 kg, the same as it is on the earth. What happens to the person's weight when they travel from the moon to earth.
Weight increases on Earth because there is more gravity.
why theories are modified, but are rarely discarded?
As long as a theory still explains a wide range of observations and evidence, it is modified and not discarded.
Ptolemy, an Egyptian astronomer, believed that all objects in space, including the Sun, revolved around Earth. Hundreds of years later, Nicolaus Copernicus, an astronomer from Poland, made observations showing that Earth and other planets revolved around the Sun, which disproved Ptolemy’s argument. What is this an example of?
Scientific knowledge changes as a result of new evidence.
Susie wanted to find the density of her silver bracelet. She found that its mass was 24 grams and its volume was 2 cm3. She knows that density equals mass divided by volume. What should her answer be if she calculated the density of her bracelet correctly?
12g/cm3