Introduction to Science

A way of learning about the natural world is called

science.

Steps to Scientific Inquiry or Scientific Method State the problem or ask a question. Research information. Form a hypothesis using IF and

THEN statement. Design and carry out an experiment. Record and interpret data. Draw a conclusion.

State the problem.

Will fertilizer help tomato plants grow?

Research information

Go to the library.Ask a resource person (college, greenhouse,

gardener, etc.)Research on the internet.

Read magazines, books, etc.

Form a hypothesis.

If fertilizer is added to the soil, then the plant will grow

taller.

Design and carry out an experiment.

Manipulated variable (independent variable)-

variable that is being changed.Responding variable

(dependent variable) –variable that changes due to the manipulated variable.

Controlled experiment

An experiment in which all variables are kept constant

except one.Examples: sunlight, soil, water, size of containers, depth of seeds, type of

fertilizer, amount of fertilizer, temperature, etc.

Collect data.

May be written observations or numbers. Metric is always

used in science.

Interpret Data

Look for patterns or trends. (Ex: the rate of growth; the

end results; the average growth, etc.)

Figure the average of your trials. Remember to at least run a minimum of three trials.The more trials, the more accurate the data.

Plants Trial 1 Trial 2 Trial 3 Average

Group A 17 20 22 19.7

Group B 30 32 35 32.3

Growth of plants (cm)

To find the average or mean, add the data for the three trials and then divide by the number of trials.17+20+22=59 59/3=19.666 or 19.7

30+32+35=97 97/3=32.333 or 32.3

Draw Conclusions

Was your hypothesis supported or not? Your

hypothesis does not always have to be right.

Scientists use a standard system of measurement called the International System of Units (SI) based on the metric system.

Metric is based on the power of 10.

Common SI PrefixesPREFIX SYMBOL MEANING

kilo k 1,000

hecto h 100

deka da 10

deci d 0.1 (one tenth)

centi cm 0.01(one hundreth)

milli mm 0.001(one thousandth)

The unit measure of length or distance is the meter (m)

This line is 3 cm or 30 mm.

The unit measure of volume of a liquid, or the amount of space it takes up is the liter (L)

Use a graduated cylinder. One liter=1,000ml

What is the volume?

The answer is 53ml.

The unit of measurement of mass, or the amount of matter in an object is the gram (g).

Triple beam scale

http://www.ohaus.com/input/tutorials/tbb/tbbentry.swf

Practice using the triple beam scale at this website. Copy and paste this link or locate this link on teacher website.

Conservation of Matter The physical law

stating that matter cannot be created nor destroyed in chemical reactions: thus, the number of particles before and after the reaction is equal.

Count up the atoms on the left of the arrow. They should equal the atoms on the right.

Four Qualities of a Scientist Reasoning-the power of thinking in

an orderly way. Reasoning starts with observations using the five senses and tries to explain those observations. (The why and how an event happens as it does.)

Four Qualities of a Scientist Creativity-the ability to imagine

possible experiments, solutions, and explanations; think of new ideas and inventions.

Skepticism-an attitude or doubt or uncertainty that leads to questioning.(Don’t always believe what you read…especially on the internet!)

Four Qualities of a Scientist Openness-the willingness to have

one’s belief’s tested and possibly changed. An open person must be ready to change his/her belief if enough evidence proves against it.

Bias The individual perspective on issues

or data that affects how we see and report our observations. (How we see the world as we wish, not as it actually is.)

Everyone has bias. A scientific community can reduce bias by repeating experiments and reproducing the same results.

Design an experiment to test the effect of acid on plants. Experimental

group has the independent variable added.

The control group does not have the independent variable added. (This is used for comparison.)

The independent variable is the variable that is changed. In this case it is the acid.

Group A With acid

Group BWithout acid

Constant variables: amount of sunlight, soil type and amount,watering schedule, containers, type of plants, age of plants

The dependent variable is the growth of the plant. (This is always how you will measure your results.)

Measure using metric. Keep accurate records of data for

both groups. Never throw out data that does not fit your results.

Do not go back and change your hypothesis to fit your data.

Find a trend/pattern.