 Chemistry is the study of the composition of matter and the changes that matter undergoes  What is matter?  Matter is anything that has mass and occupies space (volume)  Everything is made up of matter!!

 Chemistry is needed to  Explain the natural world  Prepare for a career  Be an informed citizen  Chemistry is used to  Conserve, produce, and store energy  Develop medicines, material, and technologies for medical treatment  Develop productive crops  Identify and prevent pollution  Understand the universe

 All of the digits in a measurement that are known, plus a last digit that is estimated  Used in science to increase accuracy and certainty of data

 Atlantic/Pacific Rule

 Atlantic Rule  If a decimal is absent, start from Atlantic side (right) till you reach the first non-zero digit  Every digit from thereafter is significant (including any zeros)  387,000  200  400,300

 Pacific Rule  If a decimal is present, start from the Pacific side (left) until you reach the first non-zero digit  Every digit from there after is significant (including any zeros)    4.00

 How many significant figures?   34,980,000  483,082,000,000   5,600   4,009

 Determine the amount of significant figures (Atlantic/Pacific rule) that each number from the problem has  Calculate as normal  Rule:  Express your answer by rounding to the same number of sig figs as the number with the least sig figs from the problem

1) 4040 x 21 (3) (2) = 84,840 = 85,000 2) 98.0 /.8775 = = 112 3) x 103 x 2.8 = =4.9

 Calculate as normal  Rule:  Express your answer by rounding to the same number of decimal places as the measurement with the least number of decimal places from the problem

1) = ) 42.9 – = = ) = = 85.01

 Solve the following problems, express your answer using the correct number of significant figures