Science is a process of making observations, and asking questions about those observations.
Science
is all around us.
Because of this, science is also considered a method of obtaining
knowledge about nature.
Nature includes the earth, space, and all living and non-living things.
Modern
scientists study patterns and make predictions.
There
are many branches of science, for example, biology, astronomy, geology, and
the one we are studying this year, physical science.
Physical
science
is the study of matter and energy. There
are two main branches of physical science:
1)
Chemistry
– which is the study of matter and the changes that matter undergoes.
2)
Physics
– which is the study of the many forms of energy, and the relationship
between matter and energy.
Technology
– In science we gain the information, in technology we use that information
to try and improve the quality of human life.
For
scientists to be able to do what they do, they must have a logical plan for
gathering information and testing ideas.
This logical plan is called the scientific method.
The
scientific method is divided into six key steps:
1)
Ask
a question based on an observation
– an observation is an examination of something in nature. Observations are
made through one or more of your senses.
Observations can take many forms, for example, a measurement is a
numerical observation.
2)
Form
a hypothesis
–
which is a possible answer to a question.
A good hypothesis is testable by an experiment.
3)
Test
the hypothesis by conducting an experiment
– An experiment is usually divided into two groups, the control group, which
is used for comparison because you know what the results are going to be, and
the experimental group, which is different from the control group by the one
factor you are testing. This one
factor is called a variable. The
information collected during the experiment is called data.
4)
Analyze
the results collected from the experiments
–
The data collected must be organized so they can be analyzed.
This is done using tables and graphs.
5)
Draw
conclusions from the results of the experiment
–
A conclusion is a statement that tells whether or not the data supports the
hypothesis. A hypothesis that has
been tested and supported many times becomes a theory. When the hypothesis is not supported by the data, the
scientist must find another explanation for what the observed.
6)
Communicate
results to other scientists
– This allows other scientists to verify your findings, and to help them in
their investigations.
Not
all scientists follow the scientific method, improvisation leads to
discoveries.
A
scientific theory is a unifying explanation of a broad range of
hypotheses that have been supported by testing.
Theories can be changed or modified by new evidence.
A
scientific law is a summary of many experimental results.
It tells how things work.
Laws are not like theories because they tell what happens and not why
it happens.
A scientific model is a representation of objects or systems. Models are designed to make difficult concepts easier to understand. Models can represent things too small or large to observe directly. Models build scientific knowledge by being used to test hypotheses and illustrate theories.
The International System of Units (SI), also known as the metric system, is the standard system of measurement among scientists all over the world. This is important because when scientists compare results, everyone must be talking the same language so they understand each other.
Length, volume, mass and temperature are all quantities of measurement. They each have their own SI units by which they are measured.
Area is a measure of how much surface an object has. It is calculated by using the formula:
A = L x W
Density is how much mass there is per unit volume. It is calculated by using the formula:
D = M / V