Hazards of Chemical Substances

• Flammability

• Corrosiveness

• Radioactivity

Definition of Science

Science, as defined by the National Academy of Sciences, is the “use of evidence to construct testable

explanations and predictions of natural phenomena, as well as the knowledge

generated through this process.”

Limitations of Science

Science has limitations: it cannot test all phenomena in the world nor can it

answer every question

Limitations of Science

Which of these questions cannot be tested or explained by science?

A. At what temperature does water boil?B. Why does covering a fire cause the fire to die down?C. Why does evil exist in the world?

Limitations of Science

Of the answer choice you selected in the previous slide, why can the question not be tested or explained by science?

A. It is a question of philosophy and therefore it is not in the field of scienceB. An experiment cannot be devised to test this questionC. Both of the aboveD. None of the above

Within the realm of science(scientifically testable)

Outside the realm of science(not scientifically testable)

rodents can finish a maze quicker in the morning than afternoon

humans type faster after consuming caffeine

cats can taste food better in the light than in the dark

it is immoral to leave dogs unattended in the yard all day

males will rate a female as beautiful more often is she is blonde vs. brunette

Scientific Method

♦ State the Problem

♦ Form Hypothesis

♦ Design an Experiment to Test the Hypothesis

♦ Test the Hypothesis

♦ Accept or reject the hypothesis (Draw Conclusion)

Define the Problem

Develop a question or problem that can be solved through experimentation

Ex. What is the effect of detergent on vegetable oil?

Form Hypothesis

Predict a possible answer to the problem

This is a testable solution to the problem

Example: If soil temperatures rise, then the plant growth will increase.

Characteristics of a Hypothesis

A hypothesis must be testable in a way that is replicable by others

A hypothesis is an educated guess as to why something happens

A hypothesis is an explanation for a natural phenomenon

Your hypothesis must be written before you start your experiment

Theory

A theory is based on natural and physical phenomena and states why a certain event occurs the way it does

When a significant number of scientific hypotheses over time all had similar results leading to the same conclusion, these scientific hypotheses could become a scientific theory

Theories are highly reliable explanations

Chemistry and Matter• What is chemistry?• Chemistry is the study of matter and the

changes that it undergoes.• What is matter?• Matter is anything that has mass and takes

up space• What is mass?• Mass is a measurement that reflects the

amount of matter in a substance

Chemistry and Matter

• What is the difference between weight and mass?

• Weight is a measure of the effect of the Earth’s gravitational pull on matter

• Is your weight the same at all locations?• Is your mass the same at all locations?

Design an Experiment

• Pick a partner to work with• You and your partner must design an

experiment that can be performed by others• You must list all materials that will be

needed, the purpose of the experiment, and STEP by STEP procedures for completing the experiment