Chapter 1 – Science Skills

Chapter 1 – Science Skills

1.1 – What is Science

What is Science?

A system of knowledge and the methods you use to find that knowledge

Observation and measuring are the means of scientific discovery

The root of science is curiosity!

Measurements

QUALITATIVE Descriptive

observations Think “QUALITY”

QUANTITATIVE Numerical

observation Think

“QUANTITY”

What is technology?

The use of knowledge to solve practical problems

What kind of technology do you use?

What practical problems does that technology solve?

Branches of Science

Three Branches of Science Physical Science Earth & Space Science Life Science

Scientific InvestigationsOBSERVATIONS Information that is

gained through your senses

INFERENCES Something that

you think might be true based on observations

Evidence-based guesses

Observations vs. Inferences Your group will be provided an

object. Make three observations and three inferences about this object.

The Scientific Method1.2 Using a Scientific Approach

What is the scientific method? It is a process that is used to find

answers to questions about the world around us.

Is there only one scientific method? No, there are several versions of the

scientific method. Some versions have more steps, while others may have only a few. However, they all begin with the identification of a problem or a question to be answered based on observation of the world around us and provide an organized method for conducting and analyzing an experiment.

What is a hypothesis?

It is an educated guess based on observations and your knowledge of the topic.

ADD TO NOTES A hypothesis is a proposed answer to a

question A hypothesis is only useful if it is

TESTABLE

What is data?

It is information gathered during an experiment.

ADD TO NOTES Observations▪ Information that is gained through your

senses

Steps of the Scientific Method

Identify the Problem

Form a Hypothesis

Create an Experiment

Perform an Experiment

Analyze the Data

Communicate the Results

Is the data inaccurate or the

experiment flawed?

Modify the Experiment

Testing a Hypothesis

Experimental Variables Any factors that can change in an

experiment

Two types of Variables Independent Variable (the manipulated

variable) Dependent Variable (the responding

variable)

Dancing with the Stars & Variables Kate Gosselin & Tony Dovolani - Jive (Start at 3:25)

Variables

INDEPENDENT

The variable that is purposefully changed in an experiment by the experimenter

A change in this variable results in a change in another variable

ALWAYS graphed on the Y-axis

DEPENDENT

The variable that is being measured in an experiment

This variable changes in response to changes in the independent variable

ALWAYS graphed on the X-axis

Example 1 If a scientist conducts an experiment to test

the theory that a vitamin could extend a person’s life-expectancy, then the independent variable is the amount of vitamin that is given to the subjects within the experiment. This is controlled by the experimenting scientist.

The dependent variable, or the variable

being affected by the independent variable in this case, is life span.

IV & DV Examples Game

Controlled Experiments

An experiment in which only one variable, the independent variable, is deliberately changed at a time.

Constants Experimental variables that must remain

consistent in order to test a hypothesis

Example 1

In an experiment designed to test the effect of water temperature on how fast sugar can be dissolved in a pitcher of Kool Aid, what variables should remain constant?

Example 2

In an experiment designed to test which dog food is preferred by dogs, what variables should remain constant?

Drawing Conclusions

Conclusions summarize the findings of an experiment

All conclusions should explicitly state whether or not the results of an experiment supported the original hypothesis

Scientific Theories

A well-tested explanation for a set of observations or experimental results

Theories are never proved, but rather become stronger if facts continue to support them

Facts are repeatable observations

Scientific Laws

A statement that summarizes an observed pattern found in nature without attempting to explain it.

The explanation of such a pattern is provided by a scientific theory

Precision & Accuracy1.3 Measurement

Scientific Notation

A way of expressing a value as the product of a number between 1 and 10 and a power of 10

Makes very large or very small numbers easier to work with

Examples 300,000,000 can be written as 3.0 x 108 0.00086 can be written as 8.6 x 10-4

Multiplication & Division

Multiply the numbers before the multiplication signs, then add the exponents of the 10

Divide the numbers before the multiplication signs, then subtract the exponents of the 10

Practice

A rectangular parking lot has a length of 1.1 x 103 meters and a width of 2.4 x 103 meters. What is the area of the parking lot?

4.5 x 103 / 9.0 x 10-1

SI Units of Measurement

All measurements must have both a number value and a unit

SI = International System of Units Units of measurement that are used in

scientific investigation Consists of both base units and derived

units

SI Base Units

SI Base UnitsQuantity Unit Symbol

Length Meter mMass Kilogram kgTemperature Kelvin KTime Second sAmount of Substance Mole molElectric Current Ampere ALuminous Intensity Candela cd

SI Derived Units

SI Derived UnitsQuantity Unit Symbol

Area Square meter m2

Volume Cubic meter m3

Density Kilograms per cubic meter

kg/m3

Pressure Pascal (kg/m•s2) PaEnergy Joule (kg•m2/s2) JFrequency Hertz (1/s) HzElectric Charge Coulomb (A•s) C

Metric Prefixes

Indicates how many times a unit should be multiplied or divided by 10

The easiest way to convert from one unit of measurement to another is to use conversion factors Conversion Factor: A ratio of equivalent

measurements that is used to convert a quantity expressed in one unit to another unit

SI Prefixes

SI PrefixesPrefi

xSymb

olMeaning Multiply

Unit Bygiga- G billion (109) 1,000,000,000mega- M million (106) 1,000,000kilo- k thousand (103) 1000deci- d tenth (10-1) 0.1centi- c hundredth (10-2) 0.01milli- m thousandth (10-3) 0.001micro- μ millionth (10-6) 0.000001nano- n billionth (10-9) 0.000000001

Conversion Factor Example Mount Everest is 8848 meters high.

Convert this number to kilometers. There are 1000 meters in 1 kilometer ▪ (1000 m/ 1 km)

Precision & Accuracy

Precision A gauge of how exact a measurement is

Accuracy The closeness of a measurement to the

actual value of what is being measured

Measuring Temperature

Three types of scales Fahrenheit Celsius Kelvin

You can convert between all three scales using the following formulas ºC = 5/9 (ºF – 32.0º) ºF = 9/5 (ºC) + 32.0º K = ºC + 273