Unit 7 Measurement and Math in Chemistry

When we measure, we use a tool to compare some quantity of an object to a known standard. Examples: Ruler Inch Scale Pound Beaker Mililiter Stopwatch Second Tool Standard

In Science we measure quantities and use numbers to report measurements for comparison with other results.

What are some U.S. units that are used to measure each of the following? Slug League Teaspoon City Block Kelvin Parsec Liter Cup Ounce Pound Farenheit Inch Answers Length Weight Volume Temperature

In every measurement there are two parts: 1)Number 2)Unit from measuring device 20.6 Years Example:

What is the unit of measurement in each of the following examples? A. The patient’s temperature is 102°F. B. The sack holds 5 lbs of potatoes. C. It is 8 miles from your house to school. D. The bottle holds 2 L of orange soda. A. The patient’s temperature is 102°F. B. The sack holds 5 lbs of potatoes. C. It is 8 miles from your house to school. D. The bottle holds 2 L of orange soda. Pull

Measure a Paper Clip

All measuring devices have limitations to their measurements. You are EXPECTED to estimate 1 digit beyond the known values. Measure the length of the ice cream truck: Known Estimated Unit cm

What are some U.S. units that are used to measure each of the following? League City Block Parsec Inch Teaspoon Liter Cup Slug Ounce Pound Kelvin Farenheit Question Weight Length Volume Temperature

Charleston Naples Based on my regular car odometer, if I told you I traveled miles, how may you find that odd? Discuss.

All measuring devices have limitations to their measurements. You are EXPECTED to estimate 1 digit beyond the known values. Measure the length of the ice cream truck: Known Estimated Unit cm

Significant Figures - Rules 1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant. 2) ALL zeroes between non-zero numbers are ALWAYS significant. 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. 4) 4) Leading zeroes (at the beginning of the number) are NEVER significant. E xact numbers = numbers that are NOT direct measurements are unlimited in terms of significant figs.

Significant Figures - Rules 1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant. 122 SF SF.5673 SF

Significant Figures - Rules 2) ALL zeroes between non-zero numbers are ALWAYS significant SF SF 20,000,0058 SF

Significant Figures - Rules 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. (Zeroes at the end of numbers with no decimal place are NOT significant!) SF SF SF 101 SF 5202 SF

Significant Figures - Rules 4) Leading zeroes (at the beginning of the number) are NEVER significant. (Doesn't matter if there is a decimal or not!) SF SF SF

Pull 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. Pull 4) ALL zeroes which are to the left of a written decimal point and are in a number >= 10 are ALWAYS significant. Pull 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. Pull 4) ALL zeroes which are to the left of a written decimal point and are in a number >= 10 are ALWAYS significant. Pull 4) ALL zeroes which are to the left of a written decimal point and are in a number >= 10 are ALWAYS significant. Pull 1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant. Pull 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. Pull 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. Pull 2) ALL zeroes between non-zero numbers are ALWAYS significant. Pull 2) ALL zeroes between non-zero numbers are ALWAYS significant. How many significant figures? Pull the purple tab to the left for the rule(s). Drag the number toward the green box for the answer

Let's practice identifying the number of sig figs...

Convert Decimal Moves?Direction Answer 399 km = ? cm mg = ? cg cg cL = ? L left 5,623 m = ? km 39,900,000 cm left right km L Drag the labels to the correct location in the table. Remove the shaded area below for the answers. left right39,900,000 cm L km

Scientific Notation: Invented to save YOU time = 1.0 x = 2.0 x Pull Used for writing vary large or small numbers quickly.

The number 154,000,000,000 is written in scientific notation as 1.54 x The second number (10) is called the base. It must always be 10. The base number 10 is always written in exponent form. The first number (1.54) is called the coefficient. The coefficient must be greater than or equal to 1 and less than 10. The third number is called the exponent. It is also referred to as the power of ten. (11) coefficient base exponent

Sort the given values. Written in proper scientific notation NOT written in proper scientific notation

Write this number in scientific notation by following the steps below. Step 1:Put the decimal after the first digit Step 2: Find the exponent by counting the number of places from the decimal to the end of the number. Step 3: Drop the zeros to get the coefficient. Multiply it by the base (which is always 10) and include the exponent that you found in step x

Writing a Number in Scientific Notation If you move from the right, the exponent is positive! If you move from the left, the exponent is negative!

Scientific notation is used to write really big numbers. 123,000,000,000 45,000,000 67,800,000,000,000 9,000 move the star to count the number of decimal places the amount of moves will give you the exponent value standard/decimal notationscientific notation

Scientific notation is used to write really small numbers move the star to count the number of decimal places the amount of moves will give you the exponent value standard/decimal notationscientific notation

Writing a Number in Standard Notation Standard notation means that the number is written out in it's long form. If the exponent is positive, move to the right! If the exponent is negative, move to the left!

Scientific notation is used to write really small numbers. 4.8 x x 10 9 x x 10 the exponent tells you how many decimal places you need to move Standard/decimal notation scientific notation

USING DIMENSIONAL ANALYSIS Rules for problem solving and unit conversion 1. Identify and write down the given (what are you starting with, what are you converting) in THIS problem. 2. Write......X ___________________ Units of given must go on bottom. 3.Identify the unknown. 4. Identify conversion factors and decide on a plan to get to UNITS of unknown. Make sure units cancel along the way. 5. Do the math. Multiply numbers in numerator, divide by numbers in denominator. Don't forget SF's!!!! SF's will always be based on GIVEN!!! Conversion factors are exact numbers. `

12 widgets = 1 doz. widgets

If I have 6 widgets how many doz. widgets do I have? 6 widgets 12 widgets 1 doz. widgets = 0.5 doz. widgets

= Widget 1 Widget contains 1 red doohickey 2 yellow doohickeys How many yellow doohickeys are needed to make 7 dozen Widgets? 7 doz widgets 12 widgets 1 doz widgets 2 yellow doohickeys 1 widget =

If three teaspoons are equal to one tablespoon and one cup is equal to 16 tablespoons, how many cups are 115 teaspoons? If four densos equal 10 waps, and 7 greems equal 20 densos, how many waps are there in 50 greems?