The Scientific Method



The Scientific Method

Georgia Professional Standards Addressed in this Lesson:

S7CS4: Students will use tools and instruments for observing, measuring and manipulating equipment and materials in scientific activities.

S7CS6: Students will communicate scientific ideas and activities clearly.

Science is basically the process of observing things, asking questions about the observation and conducting experiments to find answers to the questions.

Life Science - the study of living things. Life scientists conduct research or experiments that help in finding cures for diseases, conduct research to understand the components of cells, understanding how the living organisms in the environment effect each other as well as the forces or occurrences that impact living organisms.

In order to do the work of scientists, the scientific method has been designed to break the process into stages. The scientific method is often described as a series of steps that is used to answer a question or solve a problem.

There are six steps to the scientific method: 1) Ask a Question 2) Form a Hypothesis 3) Test the Hypothesis (Conduct Experiment) 4) Analyze the Results of the Experiment 5) Draw Conclusions and 6) Communicate the Results.

Ask a Question

When you observe something you do not fully understand you often ask yourself a question about what may have caused what you observed. Once you ask yourself a question, you must often do more observations while searching for the answer.

Form a Hypothesis

The hypothesis is a logical explanation for what you have observed. In other words you make a possible explanation to the phenomenon you observed. The hypothesis is usually written in the form of an If…,then statement. Example: If I take a balloon and fill it with air I can poke it with a sharp needle and then it will deflate very fast. This can be easily tested with a blown up balloon and a sewing needle.

Test the Hypothesis

When you test your hypothesis you are conducting experiments that may help you explain the phenomenon or observation. Many of the experiments scientists use are designed by the scientist working on solving the problem or phenomenon observed. This means that many scientists must be somewhat creative and often think “outside the box” to set up their experiments.

When scientists test their hypothesis, they utilize controlled experiments. A controlled experiment is an experiment that tests only one factor at a time. The one factor being tested is known as the variable. Scientists only test one variable at a time to be more certain that it is the variable causing the effect.

Analyze the Results

After the experiments have been completed, the scientist must carefully analyze the results and determine if the results help in solving the problem or answer the hypothesis.

Draw Conclusions

The scientist must look at the data gathered from the experiments and draw a conclusion based on the results from the experiment. In other words, does my data support or not support the hypothesis that was formed.

Communicate the Results

This step involves telling others in the scientific field about your experiment and your findings. At this point other scientists may want to see if they can replicate you experiment or maybe modify your experiment to see if they come up with the same conclusion(s).

Sometimes a problem may be tested over and over with scientists getting the same results. When this occurs, we call the explanation of why something occurs in a particular way a theory.

Tools that Scientists Use

Many of the tools scientists work with are often new and have been developed to work on specific research experiments. We often call this technology. Technology is the use of knowledge, tools, and materials to solve problems and accomplish tasks.

One of the most common pieces of equipment for scientists to use is a microscope. Scientists use microscopes to see things in more or greater detail. There are two main types of microscopes scientists use: 1) Compound Light microscope and 2) Electron microscope.

Compound Light Microscope – has three main parts (a tube with lenses, a stage and a light source). Specimens are often viewed with compound light microscopes that have been dyed (stained) in order to see the object better. The specimen or object is placed on the stage in order for the light to pass through it and as the image passes through the lenses, it becomes magnified.

Electron Microscope – this is where tiny particles of matter (called electrons) are passed through (with a transmission electron microscope) or bounced off of the specimen (scanning electron microscope). A flat image is produced with the transmission electron microscope and a three dimensional image is produced with a scanning electron microscope. All organisms viewed with the electron microscopes must be dead because the electrons passing through them or bombarding them will cause death or mutations.

Other Tools

X Rays allow us to detect internal structures (broken bones) or living organisms.

CT (Computed Tomography) Scans and MRI (Magnetic Resonance Imaging) these tools provide clearer images of internal tissues than X rays. These tools create images that experts can interpret.

Computers are very prevalent in science. Computers now allow scientists to model different problems and modify the influences to see what results occur. You are probably familiar with computer generated weather forecasts if you watch the weather on nightly news. Computers are also one of the fastest methods for communicating, writing research articles for journals, calculating numerical data, and organize information to name a few uses.

Systems of Measurement

Scientists are constantly measuring things (temperature, mass, velocity, volume, and length to mention several). Scientists use the metric system to take measurements. For length we use the meter as the standard, for mass we use the gram as the standard, and for temperature we use Celsius, and for volumes of solids we use cubic units and for liquid volume we use liters.

We must realize that each major unit has subunits based on the value of 10. Look at the following prefixes and know what they represent: (we will be using the prefixes with the standard length unit in this example)

Kilo = 1,000 Kilometer = 1,000 meters

Hecto = 100 Hectometer = 100 meters

Deci = 1/10th Decimeter = 1/10th of a meter

Centi = 1/100th Centimeter = 1/100th of a meter

Milli = 1/1,000th Millimeter = 1/ 1,000th of a meter

KING = KILO

HENRY = HECTO

DIED = DEKA (10)

BY = BASE ----- Grams, Liters, Meters

DRINKING = DECI (1/10)

CHOCOLATE = CENTI

MILK = MILLI

Most of these prefixes are also used with other measuring units. Example: Many times scientists need a liquid in small amounts so we measure it in milliliters (1/1,000th of a liter). We will practice with these in our homework/class work worksheets throughout the year. Remember to use the best suited unit for your measurements. We would not measure the length of a soccer field in millimeters normally, we would want it in meters. Small objects like algae or bacteria would not be measured with meters, but some subunit of meters like micrometers (1/100,000th of a meter).

Measuring Area - area is the measurement of how much surface something has. We measure area with the following formula:

Area = Length X Width or (L)(W)

Notice that this will give us SQUARE UNITS. Example: If we have a rectangle that measures 3 meters in length and 2 meters in width, we can calculate the area of the rectangle by using our formula Area (A) = (L)(W) or (3)(2) which equals 6 SQUARE meters.

Practice: Measure a regular sheet of notebook paper and calculate the square inches in centimeters. Answer: _________________ square centimeters (sq. cm.)

Measuring Volume – volume is the amount of space something occupies or as in the case of a box, the amount of space it contains. We can calculate volume by using the formula as follows:

Volume (V) = Length (L) X Width (W) X Height (H)

Notice this will require a cubic unit on the answer. Example: If I have a plastic container that measures 4 meters wide, 6 meters in length and 2 meters in height, we can calculate the volume of water the container will hold.

V = 4 meters X 6 meters X 2 meters which equals 48 Cubic meters (m3)

Scientists often have specific tools to measure liquids. The most accurate tool is the graduated cylinder. It is a cylinder with marks (often in milliliters) that we will use in lab. When in class you can see one of the graduated cylinders on page 25 of your text book.

Measuring Mass – mass is the amount of matter that makes up an object. The basic unit of mass is the kilogram. When we measure the mass of small items or organisms we may use milligrams, or in the case of our labs we usually measure in grams. The tool used to measure mass is the triple beam balance scale. We will use one of these in lab and you must know how to use it and read the scale.

Measuring Temperature – temperature is the measure of how hot or cold something is. Temperature is really a measure of how fast or slow molecules are moving. The higher the temperature, the faster those molecules are moving. We measure temperature with a thermometer and in degrees Celsius. Celsius is the metric system’s unit of scale, while Fahrenheit is the unit we use in the United States.

You should know that water boils at 212 degrees Fahrenheit, which is 100 degrees Celsius. Normal human body temperature is 98.6 degrees Fahrenheit, which is 37 degrees Celsius. Water freezes at 32 degrees Fahrenheit, which is 0 degrees Celsius.

Safety – during science class this year we must observe safety rules. No horseplay will be allowed in the science room, no eating or drinking should occur. Always follow directions your teacher outlines and discusses. If you do not understand something, ask the teacher instead of “trying” something that could result in an accident.

SCIENTIFIC METHOD WORKSHEET

1. The study of living organisms in best known as L_________ S______________.

2. The s_____________________ m_________________ is often described as a series of steps that is used to answer a question or solve a problem.

3. The six steps to the scientific method are

1. A_____ a Q_____________

2. F______ a H______________

3. T_________ the H________________

4. A_____________ the R______________

5. D_____________ C_____________________

6. C_____________________ the R____________________

4. An h__________________ is an “if…….then” statement that scientists use to try and explain an event or phenomenon.

5. A c____________________ e____________________________ is an experiment in which only one factor is tested for at a time.

6. The factor that scientists are testing during a controlled experiment is known as the v________________.

7. After a scientist completes an experiment, the scientist should a______________ the r_____________________.

8. After all the data from an experiment has been carefully reviewed or analyzed, a good scientist will d_____________ c_______________________.

9. When a scientist has made all of their conclusions, they should c___________________________ the r____________________ to other scientists as well as others interested in their research.

10. A t_______________________ is an explanation of why something occurs in a particular way and has been tested many times with the same results.

11. The use of tools, knowledge, and materials not previously available to scientists is known as t__________________________.

12. A c______________________ l__________________ m______________________________ is often used to magnify objects. This tool consists of a tube with lenses, a stage, and a light source.

13. A e_____________________ m__________________________ uses tiny particles called electrons to form a computerized image of an object being looked at.

14. X R_________ are a form of technology that allows us to form images of internal structures like bones.

15. Computers are often used in making m_________________ to see what different effects occur when different variables are applied.

16. The metric unit for measuring length is the m__________________.

17. The metric unit used for measuring mass is the g_______________________.

18. Liquid volumes are often measured in l_________________ or small amounts in m_____________________.

19. C__________________ is the metric unit we use to measure temperature in science.

20. If we want to get the area of a field that is 20 meters wide and 40 meters long we would multiply the l______________ times w__________________.

21. What is the area of the scenario in question 20? ____________________ square meters.

22. If a refrigerator has the inside dimensions of .5 meters deep, 2 meters wide and 4 meters tall, what is the volume? _______________________ cubic meters.

23. Scientists often utilize a t___________________ beam b___________________ in order to get the mass of an object in their laboratories.

24. How many centimeters are in one meter? _____________________

25. How many meters are in one kilometer? ______________________

26. Which prefix means 1/1,000th? M____________

27. Ten centimeters make up one d______________________.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download