Presentation on theme: "Starter The radius of the moon is 1,737,000 meters. Write this in scientific notation. The diameter of a carbon atom is 0.000000000154 meters. Write."— Presentation transcript:
1 StarterThe radius of the moon is 1,737,000 meters. Write this in scientific notation.The diameter of a carbon atom is meters. Write this in scientific notation.Convert the following numbers into standard notation:6.7 x 1068.8 x 10-4
2 StarterThe radius of the moon is 1,737,000 meters. Write this in scientific notation.The diameter of a carbon atom is meters. Write this in scientific notation.Convert the following numbers into standard notation:6.7 x 1068.8 x 10-41.737 x 106 meters1.54 x meters6,700,000
3 Measurement A quantity that has both a number and a unit. Fundamental to the experimental sciences.
4 Accuracy, Precision, and Error Accuracy- How close a measure comes to the actual value of whatever is measured.Precision- A measure of how close a series of measurement are to one another.XXXXXXX
5 Error = Experimental Value – Accepted Value If you boil water and the thermometer reads 99.1 C . You know that the boiling point is 100. C. What is the error?XXXXError = Experimental Value – Accepted Value
6 Error Accepted Value = 100 Experimental value = 99.1 Percent Error =ErrorAccepted Value
8 Sig FigsMeasurements must always be reported to the correct number of significant figures because calculated answers depend on the number of sig figs used in the calculations.
9 Significant FiguresHow would you record the volume of liquid in this graduated cylinder?Volume = 9.6 mLCould I have recorded the volume as 9.65 mL?What about 10 mL?
10 What are Significant Figures? Significant figures are the digits in a measurement that contribute to the precision. I promise this will make more sense after a few examples!The number of significant figures in a measurement represents how precise that measurement is.For example, a measurement of 3.1 g (2 sig figs) is less precise than a measurement of 3.12 g (3 sig figs).
11 Comparison This graduated cylinder reads: 42.9 mL This beaker reads: 23 mLWhich is more precise??
12 Counting Significant Figures Scientists need to be able to count the number of significant figures in a number. There are rules to do this.
13 Rule 1Any digit that is not zero is significant. Examples: 65.2 has 3 sig figs has 7 sig figs 7,324 has 4 sig figs
14 Rule 2Zeros that appear between any two non-zero digits are significant. Examples: has 4 sig figs has 6 sig figs has 6 sig figs
15 Rule 3Leading zeros are not significant. These zeros are sometimes called placeholders. Examples: has 1 sig fig has 3 sig figs has 4 sig figsAll these numbers have 2 sig figs!Leading zeros525.20.520.0520.0052Remember, this zero is significant!
16 Rule 4Trailing zeros in numbers containing decimals are significant. Examples: has 4 sig figs has 6 sig figs has 5 sig figstrailing zerosLeading zeros are not significant
17 Rule 5Trailing zeros in numbers that do not contain a decimal are not significant. Examples: 5100 has 2 sig figs 232,000 has 3 sig figs 70,000 has 1 sig figtrailing zeros70, has 5 sig figs
18 Significant Figures in Scientific Notation For numbers in scientific notation, determine the number of sig figs by looking at the decimal number. Examples: x 103 has 4 sig figs 2.3 x 1026 has 2 sig figs x 10-4 has 5 sig fig