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SIGNIFICANT FIGURES. What are significant figures??. The number of meaningful or reliable digits in a measurement. How to identify significant figures??. Rule 1. All nonzero digits are significant Example: 199 85 967 . 3 significant figures. 5 significant figures. Rule 2.
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What are significant figures?? • The number of meaningful or reliable digits in a measurement
Rule 1 • All nonzero digits are significant Example: 199 85 967 3 significant figures 5 significant figures
Rule 2 • All zeros between 2 nonzero digits are significant Example: 235 001 10 000 009 6 sig figs 8 sig figs
Rule 3 • All zeros before the first nonzero digit are not significant Example: 001234 0.00075 0.01201 4 sig figs 2 sig figs 4 sig figs
Rule 4 • All zeros to the right of a decimal point and a nonzero digit are significant Example: 0.200 0.03210 9.8060 800.00 3 sig figs 4 sig figs 5 sig figs 5 sig figs
Rule 5 • All zeros to the left of an unexpressed decimal point are not significant Example: 300 9900. 10100 1 sig fig 4 sig figs 3 sig figs
Stretch your muscles and have an… EXERCISE!
How many sig figs are there? • 56986 • 102 • 0.3900 • 8400 • 0.0047 5 sig figs 3 sig figs 4 sig figs 2 sig figs 2 sig figs
How many sig figs are there? • 1 090 • 0056.01 • 0.980100 • 4.00 • 0.010000 3 sig figs 4 sig figs 6 sig figs 3 sig figs 5 sig figs
How many sig figs are there? • 1400 • 2100. • 630.01 • 9.00 • 0.0501 2 sig figs 4 sig figs 5 sig figs 3 sig figs 3 sig figs
Doing mathematical operations… • Addition and Subtraction • the number of decimal places in the answer is equal to the number of decimal places in the quantity with the smallest number of decimal places Example: 1.01 + 3.111 = 0.333 + 100.3 = 4.12 100.6
Doing mathematical operations… • Multiplication and Division • the number of significant figures in the final answer should be equal to the least number of significant figures in any of the given data Example: (2.50) (2.0) = (1000)(5.00) = 5.0 5000
Q1 How many significant figures are there in this number??? 1 000 080 6 sig figs!
Q2 Add: 999.90 + 0.1 = 1000.0
Q3 How many significant figures are there in this number??? 9.0080100 8 sig figs!
Q4 Multiply! (25)(1000) = 25 000
Q5 Divide.. 999 / 3.000 = 333