# Scientific Notation Notes

• Scientific Notation
• Measurement
• Two parts
• Number
• Unit
• We work with really large and small numbers
• Scientific Notation
• Coefficient (6.022) followed by a base (10) followed by an exponent (23)
• If the exponent is positive then the number is greater than one
• If it is negative then it is a decimal
• The coefficient must be between 1 and 9, inclusive
• Sometimes in science we use spaces instead of commas
• After every third number
• Accuracy vs Precision
• Accuracy is how close a measurement is to its true value
• Precision is the ability to repeat a measurement
• In lab, she wants us to be precise
• If you are precise then that means it is most likely the fault of the instrument
• Being precise is extremely important in lab
• Accepted value is the experimentally proven true value
• The boiling point of water is 100 C
• The reference value
• The book value
• It is consistent and it is always true
• Experimental value is the value that you get in lab
• That is when a person runs a lab and they get a value for something
• Percent Error is the 1) x 100% (A-E)/(A)
• Percent Error Problem
• Lisa weighed a copper cylinder to be 46.83g. The correct mass of the cylidner is 48.32 g. Calculate the percent error.
• The percent error in this case would be roughly 3.08%
• Significant Figures
• Reporting a measurement
• Significant figures
• When we take a measurement, we always take it to the precision of the instrument plus one more
• For a ruler, we would use it to the second decimal place
• With the thermometers in the lab, we would have to measure to the first decimal place
• Significant Figures include all of the certain digits in the measurement plus the one that is uncertain.
• Rules for significant figures
• The answer can only be as accurate as the device that took the measurement
• All nonzero digits are significant
• Captive Zeros are significant (0s that have numbers around it (it is in the middle))
• 20.55 would be 4 and 200.05 would be 5
• Leading 0s are not significant
• 0.00253 would be 3 and 0.0305 would be 3
• Trailing 0s are significant when there is a decimal point
• 200.00 would have 5, 40.50 would have 4, 3400 would have 2, and 0.050600 would have 5
• Sometimes you would have to use scientific notation to get the correct number of significant figures
• Exact numbers have an infinite amount of significant figures
• conversion factors
• constants
• number of desks in the row would be exactly 5 and so it would have in infinite amount of significant figures
1)
|accepted value - experimental value|)/(accepted value