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

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. ( cm³ 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 UnitsQuantity Unit Symbol

Length meter m

Mass kilogram kg

Temperature kelvin K

Time second s

Derived UnitsQuantity Unit Symbol

Area Square meter m²

Volume Cubic meter m³

Density Kg per cubic meter Kg/m³

Frequency hertz Hz

wavelength meter m

VelocitySpeed

m/s directionm/s

v vE

Acceleration Meters per second per second

m/s² or m/s/s

Quantity Unit Symbol

Power J /s W

Force Kg.m/s² N

Momentum Kilogram meter per s Kg.m/s

Work Joule J

Energy Joule J

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. Title2. Scale3. Label units for independent & dependent

variables4. Key5. 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.