Scientific Measurement Qualitative measurement – give results in a descriptive, non- numeric form Quantitative measurement – give results in a definite form, usually numbers with units

Scientific Notation the number is written as the product of two numbers: a coefficient and 10 raised to a power the coefficient is always a number greater than or equal to 1 and less than 10 1,100,000 = 1.1 X ,000 = 6.0 X = 2.3 X 10 -4

Practice! 1,204,523 =1.20 X =7.5 X =1.23 X =7.89 X X 10 5 = 3.0 X 10 8 = 3.45 X = 9.29 X = 470, ,000,

Significant Figures Every nonzero digit is significant Zeros between nonzero digits are significant Zeros on the left in front of nonzero digits are not signficant – they are placeholders Zeros at the end of a number and to the right of a decimal are always significant Zeros at the right end of a measurement, but to the left of a decimal are not considered significant (unless they are known measured values)

Rounding Sig Figs An answer cannot be more precise (have more sig figs) than the measured values used to obtain it How to round: 1. decide how many sig figs the answer should have 2. Round to that many digits, counting from the left 3. If the digit to the right of the last sig digit is less than 5, drop it 4. If the digit to the right of the last sig digit is 5 or greater, increase the last digit by one

Measuring Temperature Celsius: 0 o - water freezes 100 o - water boils

The Metric System Prefixes: kilo1,000k hecto 100h deka 10 da (unit) 1 (m,L,g) deci 1/10d centi 1/100c milli 1/1000m

Units of the Metric System Meterlengthm Grammassg LitervolumeL Celsiustemperature o C LARGER unit smaller unit decimal smaller unitLARGER unit decimal