Introduction to Science Chapter 1

What is Science??? Science is the knowledge obtained by observing natural events and conditions in order to discover facts and formulate laws or principles that can be verified or tested.

Tracks like these are common in parts of New England and in the southwestern United States. What do you OBSERVE? What can you INFER?

Now what do you think?

Infer what happened based on your observations.

Natural Science Biological Physical Earth Ecology Geology Physics Chemistry Botany Zoology Meteorology

Science and Technology work together! Pure science studies the world for knowledge only. Technology is the application of science for practical purposes.

Scientific Laws A scientific law is a summary of many experimental results and observations; a law tells how things work.

Scientific Theory A scientific theory is an explanation for some phenomenon that is based on observation, experimentation, and reasoning.

Models A scientific model is a representation of an object or event that can be studied to understand the real object or event. Models represent things that are too small, too big or too complex to study easily.

The Scientific Method

Hypothesis A hypothesis is a possible answer to a problem that can be tested.

Controlled Experiment Scientists test a hypothesis by doing a controlled experiment. In a controlled experiment, all variables that can affect the outcome of the experiment are kept constant, or controlled, except for one. A variable is a factor that changes in an experiment in order to test the hypothesis.

Units of Measurement Scientists use the International System of Units, abbreviated SI.

SI Prefixes SI uses prefixes to express very small or very large numbers. These prefixes are multiples of 10.

Quantitative Measurements Length: a measure of the straight-line distance between two points; measured in meters. Mass: a measure of the amount of matter in an object; measured in kilograms. Volume: a measure of the size of a body or region in three-dimensional space; measured in cubic meters or Liters. Weight: a measure of the gravitational force exerted on an object; measured in Newtons.

Graphs Graphs present scientific data in easy to interpret format. Line graph Bar graph Pie Chart

Scientific Notation Scientific Notation is a method of expressing a quantity as a number multiplied by 10 to the appropriate power.

How accurate are our measurements? Data is accurate if it is close to a known value. Data is precise if it is close to other measurements during the same experiment.

Significant Figures Significant Figures allow us to determine to which decimal place we are to round our number.

Significant Digits THE RULES All nonzero digits are significant. All zeroes between sig. digs are significant. All zeroes to the right of the decimal at the end of the measurement are significant. Zeroes which only hold place value are NOT significant.

Rules for Math Operations with Sig Digs Multiplication and Division Your answer must have the same number of sig digs as the least precise measurement.

Rules for Addition and Subtraction Add or Subtract and get an answer. Round your answer to the PLACE VALUE that is least accurate from the numbers given.