Notes For

Scientific Notation

There are some very large numbers in chemistryFor Example:

The number of atoms of hydrogen in a 1.01 g sample is

602,000,000,000,000,000,000,000Can you read this number? It’s HUGE!How huge is it?

There are some very small numbers in chemistryFor Example:

The radius of an electron is

0.000 000 000 000 281 8 cmCan you read this number? It’s incredibly small!

SCIENTIFIC NOTATION

takes very large numbers and very small numbers and writes them in a way that is easier to read and perform calculations.

Scientific Notation expresses numbers as a multiple of two factors:(1) A number between 1 and 10 , and(2) Ten raised to some power, or exponent

Scientific Notation expresses numbers as a multiple of two factors:(1) A number between 1 and 10 , and(2)Ten raised to some power, or exponent

602,000,000,000,000,000,000,000 Hydrogen atoms

Is expressed as 6.02 x 1023 Hydrogen atoms It’s big but you can tell at a glance how big

1023 tells you to move the decimal 23 places to the right to express the number without an exponent

Scientific Notation expresses numbers as a multiple of two factors:(1) A number between 1 and 10 , and(2) Ten raised to some power, or exponent

0.000 000 000 000 281 8 cmIs expressed as 2.816 x 10-13 cmIt’s small but you can tell at a glance how small

10-13 tells you to move the decimal 13 places to the left to express the number without an exponent

SCIENTIFIC NOTATION

You should be able to compare decimal numbers and numbers expressed in Scientific Notation

Compare:3.00 X 108 m/s 6.34 X 1012 Wvs vs300,000,000 m/s 6,340,000,000,000 WSame Number Same Number

SCIENTIFIC NOTATION

The speed of light is 29,979,250,000 cm/sec How would this be written in Scientific Notation?

ANSWER: 2.997925 x 1010 cm/sec

SCIENTIFIC NOTATION EXAMPLES

distance to moon is 225,000 miles = ________________

In Scientific Notation?

SCIENTIFIC NOTATION EXAMPLES

USE YOUR SCIENTIFIC CALCULATOR IN THE SCI MODE TO PERFORM THE FOLLOWING CALCULATIONS.

SCIENTIFIC NOTATION CALCULATIONS

(2.15 x 105) + (3.20 x 105) = (5.07 x 104) - (1.88 x 106) =

(3.14 x 10-2) + ( 6.23 x 10-8) = (6.11 x 1012) - (2.12 x 1010) =

SCIENTIFIC NOTATION CALCULATIONS

(2 x 102) (4 x 104) =

(2.5 x 10-2) (2.0 x 108) =

(4.2 x 104) / (2.1 x 102) =

(9 x 105) / (3 x 10-2) =