SCIENTIFIC NOTATION AND CONVERSION FACTORS AN INFORMATIVE POWERPOINT BROUGHT TO YOU BY LAUREN CALVERT, HALEY DAVIS, AND DEANNA HEBERT!

SIGNIFICANT FIGURES Significant Figures in a measurement consist of all the digits known with certainty plus one final digit, which is somewhat uncertain or is estimated. The rules of sig figs are found on page 47.

SCIENTIFIC NOTATION A method of writing or displaying numbers in terms of a decimal number between 1 and 10 multiplied by a power of 10 Example! The scientific notation of 10,492 is 1.0492 × 104. FOR MORE HELP VISIT HERE

ANDDD THIS IS HOW YOU DO IT! Changing numbers from scientific notation to standard notation. Ex.1  Change 6.03 x 107 to standard notation. Remember,  107 = 10 x 10 x 10 x 10 x 10 x 10 x 10 = 10,000,000 So, 6.03 x 107 = 6.03 x 10,000,000 = 60,300,000 Answer = 60,300,000 Instead of finding the value of the base, we can simply move the decimal seven places to the right because the exponent is 7. So, 6.03 x 107 = 60,300,000 Try one with a negative exponent. Ex.2 Change 5.3 x 10-4 to standard notation. The exponent tells us to move the decimal four places to the left. So, 5.3 x 10-4 = 0.00053

CALCULATING WITH SCIENTIFIC NOTATION Rule for Multiplication - When you multiply numbers with scientific notation, multiply the coefficients together and add the exponents.  The base will remain 10. Rule for Division – When dividing with scientific notation, divide coefficients and subtract the exponents. The base will remain 10. Rule for Addition and Subtraction - when adding or subtracting in scientific notation, you must express the numbers as the same power of 10.  This will often involve changing the decimal place of the coefficient.

PRACTICE PROBLEMS TRY THIS PROBLEM

CONVERSION FACTORS

MOLES TO GRAMS EXAMPLEEEE AMOUNT IN MOLES * MOLAR MASS (g/mol) = MASS IN GRAMS EXAMPLEEEE FIRST THE MOLAR MASS OF O2 MUST BE CALCULATED. THE MOLAR MASS OF O2 IS THEREFORE 32.00 g/mol. THE ANSWER IS CORRECTLY GIVEN TO THREE SIG FIGS AND IS CLOSE TO AN ESTIMATED VALUE OF 75 g (2.50 mol x 30 g/mol).

Grams to Moles To convert a known mass of a compound in grams to an amount in moles, the mass must be divided by the molar mass. Or you can invert the molar mass and multiply so that units are easily canceled. EXAMPLEEEEE