Presentation on theme: "Scientific Notation Really large, and really small numbers."— Presentation transcript:
Scientific Notation Really large, and really small numbers
Why? u Chemistry often deals with very large and very small numbers. u There are 602,000,000,000,000,000,000,000 molecules of water in 18 mL u one electron has a mass of g u We need a shorter way of writing these numbers
Standard Exponential Form u another name for scientific notation. u consists of two parts u a number between 1 and 10 u multiplied by 10, raised to some power u 602,000,000,000,000,000,000,000 = 6.02 x u g = 9.11 x
Putting a number into scientific notation u determine how many times you have to move the decimal place to make it into a number between 1 and 10 u u use that as the power of 10 u 3.24 x 10 6
What is the number is smaller? u if you make the number bigger by moving the decimal point, make the exponent smaller and visa-versa u u 4.5 x 10 -4
Getting back to original number u Move the decimal point the same number of times as the exponent u If the exponent gets bigger the number gets smaller u Change 2.99 x 10 8 u Change 4.87 x 10 -3
Using your calculator u EE and EXP button stand for x 10 to the u 4.5 x u push 4.5 u push either EXP or EE u push 4 +/- or -4 u see what your display says.
Practice these problems u (4.8 x 10 5 ) x (6.7 x ) u (6.8 x ) (3.2 x 10 4 ) u Remember when you multiply you add exponents u 10 6 x u When you divide you subtract exponents.
Adding and Subtracting u You cant add or subtract numbers until they are to the same power of ten. u Your calculator does this automatically. u (4.8 x 10 5 ) + (6.7 x 10 6 ) u (6.8 x ) -(3.2 x ) u Remember- standard form starts with a number between 1 and 10 to start.