Science Skills

Technology Use of knowledge to solve practical problems. Science and technology are interdependent Advances in one lead to advances in the other

Models Make it easier to understand things that might be too difficult to observe directly. Computer models can show Earth moving Allows to see things that are too small (atoms) Allows to see situations that are dangerous or not possible to show. (ocean floor)

Models representation of object or system Can be: Physical: airplanes, drawings, cell, volcanoes, steam engine, skyscraper Mathematical: Weather predictions, punnett square Conceptual: systems of ideas, making comparisons with familiar things to help illustrate or explain

Safety 1. Never start without teacher 2. Read directions and assign jobs 3. Fire and Heat /Electrical Precautions 4. Chemical Precautions 5. Proper equipment, goggles, gloves 6. No running, playing, eating, throwing items 7. Clean Up and disposal

International system of units (SI) Used in many countries to have a uniform scale of measurement.

Conversions: Units based on 10

Measurement Volume: Measure of the amount of space an object takes up. For regular shaped solids use the equations L X W X H but for an irregular shaped solid you use a graduated cylinder and measure how much water is displaced. ( cm ³ or ml) 1 ml = 1 cm³ Mass: The measure of the amount of matter in an object. The tool used is a triple beam balance. (Grams g) Length: distance between two or more points. (meter m)

SI Base Units QuantityUnitSymbol Lengthmeterm Masskilogramkg TemperaturekelvinK Timeseconds

Derived Units QuantityUnitSymbol AreaSquare meterm² VolumeCubic meterm³ DensityKg per cubic meterKg/m³ FrequencyhertzHz wavelengthmeterm Velocity Speed m/s direction m/s v v̅ AccelerationMeters per second per second m/s² or m/s/s

QuantityUnitSymbol PowerJ /sW ForceKg.m/s²N MomentumKilogram meter per sKg.m/s WorkJouleJ EnergyJouleJ

Organizing Data Data Tables: easier to spot trends in the data that can support or disprove a hypothesis.

D R Y M I X Dependent variable ( outcome) Responding Variable Y – axis Manipulated variable Independent Variable (test) X - axis

Graphing DO’S 1.Title 2.Scale 3.Label units for independent & dependent variables 4.Key 5. Label the X & Y axis

Graphs Line Graph: shows changes that occur in related variables. Data that will change over time and not stay the same. ( Temperature) The Independent (manipulated) variable is on the x x-axis (horizontal axis ). The dependent (r) variable is on the y y-axis (vertical axis).

Bar Graph Used to compare a set of measurements, amounts, or changes. Allows us to analyze data quickly.

Circle/ Pie Graph A divided circle that shows how a part or percent of something relates to the whole.

Doing Science Descriptive Research: answers through observations.

Observation Uses your senses: sight, smell, sound, touch, taste Qualitative: a quality such as color, shape, smell. Quantitative: a number or quantity such as 20 students are in this class. Observations lead to inferences (guess).

Observations Systemic observation: observations obtained by following a preplanned method of observation. Empirical Evidence: Evidence based on observations of experiments rather than theory.

Inferences A guess based on your observations. Example: The students are tired because they were up late study for their science exam.

Hypothesis An educated guess base on observations. Use an if then statement. If independent variable then dependent variable.

Experimental Research To answer questions by testing a hypothesis through the use of scientific method. Perform a controlled experiment by changing one variable (independent variable), using a control group, constants, and dependent variable. Trials: do multiple trials (repeat) to make study reliable.

Variables Independent variable/test variable: The variable manipulated by the experimenter in order to study changes in the outcome variable. Dependent variable/outcome variable: A factor, usually being measured or observed that responds to, or depends on, another factor (test variable).

Multiple Trials Repetition: Making multiple sets of measurements or observations in a scientific investigation. Replication: The reproduction of a scientific investigation by another person to ensure accuracy.

C & C Constants: Factors that need to be kept the same in an experiment. Example: amount of sunlight, amount of water, and type of plant. Control or Control Group: receives normal conditions and used for comparison. Example a group that does not receive a medication to lower high blood pressure.

Law vs. Theory Law: A statement that describes invariable relationships among phenomenon, or scientific problem that can be tested by further investigation. Theory: A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.

Bias Scientists may expect certain results which effects the outcome of their experiment. Avoid by making careful measurements and choosing random samples.