Measurements in Science Chapter 1

How many jumps does it take? Ladder Method 1 2 3 KILO 1000 Units HECTO 100 Units DEKA 10 Units DECI 0.1 Unit Meters Liters Grams CENTI 0.01 Unit MILLI 0.001 Unit How do you use the “ladder” method? 1st – Determine your starting point. 2nd – Count the “jumps” to your ending point. 3rd – Move the decimal the same number of jumps in the same direction. 4 km = _________ m Starting Point Ending Point How many jumps does it take? 4. 1 __. 2 __. 3 __. = 4000 m

Conversion Practice Try these conversions using the ladder method. 1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm 14 km = _______ m 109 g = _______ kg 250 m = _______ km Compare using <, >, or =. 6 cm 6 m 7 g 698 mg

SCIENTIFIC NOTATION CHAPTER 1 c. gerlach

SCIENTIFIC NOTATION Scientific notation is a value written as a simple number multiplied by a power of 10. Scientific notation is used in science to: Express very large measurements. Express very small measurements. 3 parts to a number in scientific notation: 3.0 x 102 Coefficient Base Exponent

SCIENTIFIC NOTATION 2500 (3 moves – to the left = +3) 2.5 x 103 When writing numbers in scientific notation, move the decimal so there is 1 nonzero digit to the left of the decimal. The exponent is determined by how far you move the decimal and in what direction. 2500 (3 moves – to the left = +3) 2.5 x 103

SCIENTIFIC NOTATION 0.042 2 moves – to the right= -2 4.2 x 10-2 When writing numbers in scientific notation, move the decimal so there is 1 nonzero digit to the left of the decimal. The exponent is determined by how far you move the decimal and in what direction. 0.042 2 moves – to the right= -2 4.2 x 10-2

Introduction to Physical Science CHAPTER 1

SCIENCE Science is a system of knowledge based on facts and principles. Physical Science is the study of nonliving matter. Branches of physical science include: Physics: the study of forces and energy. Chemistry: the study of matter and its changes.

THEORIES VS. LAWS Scientific theories are explanations for some phenomena based on observation, experimentation, and reasoning. Scientific law is a summary of an observed natural event. Laws are not the same as theories because laws tell only WHAT happens, not WHY it happens. THEORY VS LAW 10

THE SCIENTIFIC METHOD The scientific method is a series of logical steps to follow in order to solve problems.

THE SCIENTIFIC METHOD Steps of the Scientific Method: State the problem Do background research Form a hypothesis Design an investigation Collect data Analyze Data Identify new questions raised by the conclusions for further investigation. Communicate results

SCIENTIFIC INQUIRY VOCABULARY An observation is to detect, discover or determine the existence using your 5 senses.

SCIENTIFIC INQUIRY VOCABULARY Inference is the act or process of drawing a conclusion based solely on what one already knows. Example: When it is cloudy, you infer that it will rain.

SCIENTIFIC INQUIRY VOCABULARY A hypothesis is a possible explanation that can be tested by observation or experimentation.

PARTS OF AN EXPERIMENT The independent variable (manipulated variable) is the variable that is intentionally changed in the experiment. The dependent variable (responding variable) is the variable that is measured or affected in the experiment.

PARTS OF AN EXPERIMENT The control is the standard against which the researcher compares the results from each treatment group (level) in the experiment. Constants are the things that are kept the same each time one of the trials in the experiment is repeated.

PARTS OF AN EXPERIMENT Example: An effervescent tablet (Alka-seltzer) releases carbon dioxide when it dissolves in liquid. We noticed that the tablet did not always dissolve at the same rate. Based on our knowledge of dissolving a solid, we wanted to see if temperature would have an effect on the rate of dissolving. What would our hypothesis be? What would our independent variable be? What would our control be? What are some constants in this experiment?

Accuracy and Precision Accuracy: A description of how close a measurement is to the true value of the quantity measured. Precision: The exactness of a measurement.

Qualitative vs. Quantitative Data Qualitative Data: data that cannot be measured on a numerical scale Quantitative Data: data measured or identified on a numerical scale. Examples (qualitative or quantitative?): “The temperature in this room is 23 degrees Celsius." “This room is warmer than it is outside". “The tree is taller than the building." "The tree is 30 feet tall."

Graphing Numerical data collected from an experiment is arranged into a data table so that its information can be read quickly.

Graphing A line graph is best for displaying that change. A line graph usually consists of two axes upon which the different variables of the experiment are graphed: The independent variable is always placed on the X axis. The dependent variable is always placed on the Y axis.

Graphing A bar graph is useful when you want to compare data for several individual items or events.

Graphing A pie chart or circle graph is ideal for displaying data that are parts of a whole.