Writing Numbers in Scientific Notation: 12 340 1. Locate the decimal point. 12 340. 2. Move the decimal point to obtain a number between 1 and 10. 1.234 3. Multiply the new number by 10n . Where n is the number of places you moved the decimal point. 1.234 x 104 (only one digit before the decimal, but not zero.)

Writing Numbers in Scientific Notation, Continued 0.000 123 40 1. Locate the decimal point. 2. Move the decimal point to obtain a number between 1 and 10. 1.2340 3. Multiply the new number by 10n . Where n is the number of places you moved the decimal point. 1.234 0 x 10-4 (only one digit before the decimal, but not zero.) Tro's "Introductory Chemistry", Chapter 2

Practice—Write the Following in Scientific Notation 123.4 145 000 25.25 1.45 = 1.234 x 102 8.001 2 0.002 34 0.012 3 0.000 008 706 = 8.0012 x 100 = 1.45 x 105 = 2.34 x 10-3 = 1.23 x 10-2 = 2.525 x 101 = 8.706 x 10-6 = 1.45 x 100 Tro's "Introductory Chemistry", Chapter 2

Tro's "Introductory Chemistry", Chapter 2 Exponents: When the exponent on 10 is positive the number is larger than one. Sun’s diameter = 1.392 x 109 m = 1 392 000 000 m Decimal point moved 9 places to the right Tro's "Introductory Chemistry", Chapter 2

Tro's "Introductory Chemistry", Chapter 2 Exponents When the exponent on 10 is negative the number is smaller than one. Average atom’s diameter = 3 x 10-10 m = 0.000 000 000 3 m. Decimal point moved 10 places to the left. Tro's "Introductory Chemistry", Chapter 2

Practice—Write the Following in Standard Form 2 100 4.02 2.1 x 103 = 9.66 x 10-4 = 6.04 x 10-2 = 4.02 x 100 = 3.3 x 101 = 1.2 x 107 = 0.000 996 33 0.060 4 12 000 000 Tro's "Introductory Chemistry", Chapter 2