Science - A Way of Thinking
What is the order of the scientific method?
Observation, Research, Hypothesis, Experiment, Data Collection, Conclusion, Communication
How many significant figures does the following number have? 0.00345
3
Which type of property (physical or chemical) does not change the composition of the matter?
Physical
What is a pure substance made of 2 or more elements chemically combined in a specific ratio (Ex. Water)?
Compound
____________ is a measure of how close measurements come to each other when they are made in the same way.
Precision
To test a hypothesis, a scientist changes ____ in the experiment
Independent variable - the variable that scientists change in the experiment
How many significant figures does the following number have? 1.2500 x 10^3
5
Density: Chemical or Physical Property
Physical
What is a well-mixed mixture containing a solvent and at least one solute that has the same properties throughout (Ex. Sugar water)?
Solution
Experiment to determine if sugar dissolves faster in warm or cold water. What is the dependent variable?
The rate at which sugar dissolves
Lilly was trying to explain to her friend the difference between a theory and a law in science. She used the theory of plate tectonics and the law of superposition as examples. Lilli explained the difference by using non-scientific language. Which statement could Lilly use to correctly describe the difference between a theory and a law in science?
A theory explains a natural event, while a law describes it.
Round 1289 to three significant figures
1.29 x 10^3
Chemical or physical property? Toxicity: how harmful or poisonous a substance is to living things
Chemical
Sugar, water and Kool-Aid mix together in a way where each substance can not be seen. What type of mixture is this?
Homogeneous
Convert 10 C to F
18° F
How are theories and laws similar? (5)
Both are widely accepted by the scientific community.
Both are based on tested hypotheses.
Both are supported by large amounts of data and evidence.
Both could be shown to be wrong at some time if there are new data to suggest so.
How would you write 0.0005 in scientific notation?
5 x 10^-4
Is lighting candles a chemical or physical change? Explain.
Chemical - the wax molecules are undergoing a chemical change; they are changing into different molecules by reacting with a substance in the air.
How are compounds different from mixtures?
Mixtures are not chemically combined
Mass is usually measured with a
Balance scale
Joe tells Gabby his theory about why sea turtles nest on the beach instead of in the ocean. He says, “The turtle eggs would sink to the bottom of the ocean, and the baby turtle would drown. I know this because my uncle is a fisherman, and he told me this information. Gabby tells Joe that his theory is not scientific. Why does Joe’s idea not meet the requirements to be a scientific theory?
Joe's idea isn't supported by scientific evidence
(6.9 x 10^7) / (2.3 x 10^-3)
3 x 10^10
Jack leaves solid butter near a warm surface. When Jack returns, the butter has turned into a liquid. Jack's friend Elijah insists this is a chemical change. Is Elijah right? Why or why not?
No, because no new matter was formed
Two clear solutions are mixed together in a beaker. Which would most likely indicate a chemical change had occurred?
Change in color
An explanation of an event or phenomenon that is well supported by data and explain why
Theory