1. Tro's Introductory Chemistry, Chapter 2 1 Scientific Notation A way of writing large and small numbers.

2. Tro's "Introductory Chemistry", Chapter 2 2 Big and Small Numbers Writing large numbers of zeros is tricky and confusing. – Not to mention there’s the 8-digit limit of your calculator! The sun’s diameter is 1,392,000,000 m. An atom’s average diameter is 0.000 000 000 3 m.

3. Tro's "Introductory Chemistry", Chapter 2 3 The steps to be taken are: 12340 1.Locate the decimal point. 12340. 2.Move the decimal point to obtain a number between 1 and 10. 1.2340 3.Multiply the new number by 10 n. – Where n is the number of places you moved the decimal point. 1.2340 x 10 4 4.If you moved the decimal point to the left, then n is +; if you moved it to the right, then n is −. 1.2340 x 10 4 Writing a Number in Scientific Notation: Example: Write 12340 in scientific notation

4. Tro's "Introductory Chemistry", Chapter 2 4 Writing a Number in Scientific Notation, Continued 0.00012340 1.Locate the decimal point. 0.00012340 2.Move the decimal point to obtain a number between 1 and 10. 1.2340 3.Multiply the new number by 10 n. – Where n is the number of places you moved the decimal point. 1.2340 x 10 4 4.If you moved the decimal point to the left, then n is +; if you moved it to the right, then n is −. 1.2340 x 10 -4

5. Tro's "Introductory Chemistry", Chapter 2 5 Practice—Write the Following in Scientific Notation 123.4 145000 25.25 1.45 8.0012 0.00234 0.0123 0.000 008706

6. Tro's "Introductory Chemistry", Chapter 2 6 Writing a Number in Standard Form 1.234 x 10 -6 Since exponent is -6, make the number smaller by moving the decimal point to the left 6 places. – When you run out of digits to move around, add zeros. – Add a zero in front of the decimal point for decimal numbers. 000 001.234 0.000 001 234

7. Tro's "Introductory Chemistry", Chapter 2 7 Practice—Write the Following in Standard Form 2.1 x 10 3 9.66 x 10 -4 6.04 x 10 -2 4.02 x 10 0 3.3 x 10 1 1.2 x 10 0