Chapter 2: Scientific Notation

# x 10n # = greater than or equal to 1 and less than 10. n = any number …-2,-1,0,1,2…

Scientific Notation .00000775 m 20 700 000 000 000 000 000 m

Scientific Notation and Significant Digits When a measurement is expressed in scientific notation all the digits in the number are significant however the 10n is not a part of the significant digits in that it only tells use how to move the decimal point. 3.60 x 1025 mg

Scientific Notation and Significant Digits Scientific Notation eliminates the need to use a bar over the zero to make the zero significant. 1000g

Scientific Notation .00000775 m 20 700 000 000 000 000 000 m

Scientific Notation 7.75 x 10-6 m 2.07 x 1019 m

Scientific Notation 7.75 x 10-6 m 2.07 x 1019 m Now multiply them together

(7.75 x 10-6 m) x (2.07 x 1019 m) = 1.60425 x 1014

(7.75 x 10-6 m) x (2.07 x 1019 m) = 1.60425 x 1014 1.60 x 1014 m2

Write the number in scientific notation. There are 802 000 000 000 000 000 000 000 copper atoms in this sample of copper sulfate.

8.02 x 1023 Cu atoms There are 802 000 000 000 000 000 000 000 copper atoms in this sample of copper sulfate.

Write the number in scientific notation. The mass of a proton is 0.000 000 000 000 000 000 000 001 672 67g

1.67267 x 10-24g The mass of a proton is

Practice Problem 8.02 x 1023 copper atoms

Practice Problem 8.02 x 1023 copper atoms Each copper atom contains 29 protons

Practice Problem 8.02 x 1023 copper atoms Each copper atom contains 29 protons Mass of a proton is 1.67267 x 10-24 grams

Practice Problem 8.02 x 1023 copper atoms. Each copper atom contains 29 protons Mass of a proton is 1.67267 x 10-24 grams What is the mass of all of copper’s protons in the sample?

Practice Problem 8.02 x 1023 copper atoms. Each copper atom contains 29 protons Mass of a proton is 1.67267 x 10-24 grams What is the mass of all of copper’s protons in the sample? (8.02 x 1023)(29)(1.67267 x 10-24 g)

Practice Problem 8.02 x 1023 copper atoms. Each copper atom contains 29 protons Mass of a proton is 1.67267 x 10-24 grams What is the mass of all of copper’s protons in the sample? (8.02 x 1023)(29)(1.67267 x 10-24 g) = 38.90295886g

Practice Problem 8.02 x 1023 copper atoms. Each copper atom contains 29 protons Mass of a proton is 1.67267 x 10-24 grams What is the mass of all of copper’s protons in the sample? (8.02 x 1023)(29)(1.67267 x 10-24 g) = 38.90295886g = 38.9g

Homework Worksheet: Significant Digits and Rounding (due tomorrow). Worksheet: Scientific Notation (due in two days).