Scientific Method & Experiments
The method scientists uses to solve problems is know as the...
Scientific Method
Define accuracy.
A measurement that is close to the true value.
How many sig figs are in 3.250 cm?
4
What is the unit of mass?
grams
Which part of a Bunsen burner should you adjust to change the color of the flame?
Air adjustment
In an experiment testing car speed on different surfaces, what is the independent variable?
The surfaces.
Define precision.
A measurement that is consistent.
How many sig figs are in 0.039 m?
2
What is the unit of density.
g/mL
Which part of the flame is the hottest?
The tip of the inner blue cone
A statement predicting how sandpaper, rubber, and waxed wood affect a toy car’s travel time is called a ______.
Hypothesis
A balance repeatedly gives 6.123 g when the actual mass is 6.543 g. Is it accurate, precise, both, or neither?
Precise, not accurate.
How many sig figs are in 302.10100
8
What is the density of a sample with mass = 200 g and volume = 150 mL?
1.33 g/mL
Give 2 examples of basic Bunsen burner safety rules.
Answers will vary.
A toy car is rolled down slope with varying surfaces and the speed is measured.
Name two controlled variables in this experiment.
Answers will vary.
What type of observation uses descriptive words like “blue” or “tall”?
qualitative
6.703 cm × 2.598 cm × 0.065 cm. How many sig figs does the final answer have?
2
A block has a density of 5.00 g/cm3 and mass of 13.5 g. What is its volume?
2.70 cm3
Name the tool you would use to transfer salt from a beaker to a weight boat.
Scoopula
Explain why it would be important to use the same balance throughout an experiment.
To maintain precision and consistency, otherwise error increases.
Which type of observation uses numbers, like 23.4 miles per gallon?
quantitative
1 x 13.25 x 2.5 x 3.70.
Write the answer with the correct amount of sig figs.
100
Two pieces of unknown metal are found to have the same density. What can be said about the two pieces of metal? Why?
They are made of the same material. Because density is a property of matter and is the same for a specific material no matter the size.
Explain why it is unwise to measure liquid volume using a beaker instead of a graduated cylinder.
Beakers have low precision and larger uncertainty; using one could give incorrect density calculations or concentration values, affecting results