Do Now & Announcements Turn in HW to be checked Sig Figs Quiz Scientific Notation, Unit Conversions Continued Tomorrow: Review Unit 1 TEST MON 8/31

Telephone 602,000,000,000,000,000,000,000 6.02 x 1023

Scientific Notation Scientific notation is used to express very large or ­very small numbers more easily. It is written as a (decimal between 1 & 10) x 10 raised to an exponent

How to express a number in terms of scientific notation: 1. Move the decimal point of your number so that you have a decimal between 1 and 10

How to express a number in terms of scientific notation: 2. Count the number of spaces (n) and which direction you moved the decimal point

How to express a number in terms of scientific notation: 3. If you moved the decimal point to the left multiply (x) your decimal by 10n 360,000  3.6 x 105 If you moved the decimal point to the right, multiply (x) your decimal by 10—n 0.00037  3.7 x 10—4

Category Normal Number Scientific Notation Population of the World 7,125,000,000 people   Distance from the Earth to the Moon 240,000 miles Raindrops in a Thundercloud 6,000,000,000,000 drops Density of Oxygen 0.001332 g/cm3 Mass of a Dust Particle 0.000000000753 kg

How to express a value given in scientific notation as a normal number: 1. Identify the exponent 3.6 x 105: exponent 5 3.7 x 10—4: exponent –4

How to express a value given in scientific notation as a normal number: 2. If the exponent is a positive number, move the decimal point the same number of places to the right 3.6 x 105: move decimal 5 places to the right

How to express a value given in scientific notation as a normal number: 3. If the exponent is a negative number, move the decimal point the same number of places to the left. 3.7 x 10—4: move decimal 4 places to the left

Category Normal Number Scientific Notation Speed of Light   3.00 x 108 m/s Distance from the Earth to the Sun 9.3 x 107 miles Cells in the Human Body 1.0 x 1014 cells Water on Earth’s Surface 1.40 x 108 square miles Diameter of a Grain of Sand 2.4 x 10-3 inches

x1000 x10 x10 x10 x10 x10 x10 x1000 x1000 Prefixes at the top of the chart represent a larger amount or quantity. Prefixes at the bottom of the chart represent a smaller amount or quantity.  

Dimensional Analysis (aka Factor-Label Method, Unit-Factor Method) Can be used to convert from one unit to another; it is based on the idea of cancelling out units! It is super important to WRITE OUT ALL UNITS when doing this!

Ex: Convert 1609 meters into kilometers

Ex: Convert 1609 meters into kilometers

Ex: Convert 1609 meters into kilometers

Ex: Convert 1609 meters into kilometers

Unit Conversion Lab Express your final answer using the correct # of sig figs and units Note: don’t look at the “conversion factors” when determining lowest # of sig figs…only look at the given or measured value.