Scientific evidence is usually the result of observation or experimentation combined with reasoning, rather than opinion. It is frequently introduced with words like "indicates" or "demonstrates" rather than "proves" due to the unprovable nature of scientific hypotheses. Research has demonstrated several negative health impacts of smoking, such as increased heart rate and damage to lung tissue, and confirmed that cigarette tar is carcinogenic. Smokers also often become physically and psychologically dependent on cigarettes and suffer withdrawal symptoms when attempting to quit. Scientists use deductive and inductive reasoning to move from evidence to conclusions, where deductive reasoning moves from general premises to specific conclusions and inductive reasoning moves from specific observations to general conclusions.

1. Give Evidence

2. Definition of evidence
Evidence is usually the result of observation or experimentation , combined
with reasoning.

3. Using English To Give Evidence
Note :
(that scientific evidence must be fact, not opinion)
Smoking is related to many heart and circulatory ailments.
(evidence is frequently introduced with words like indicates or demontrates rather than the
stronger word proves. This reflects the “unprovable” nature of most scientific hypotheses)

4. It has been demonstrated that nicotine increases the rate of the heart....
It can damage the tiny hairs (cilia) that line the breathing passages....
Research also confirms that the tar in cigarette smoke is carcinogenic.....

5. Smokers often become phisically and psychologically dependent on their
habit....
(evidence is not always marked with a clue word and often can only be identified by the
context of the paragraph)
Smokers often... Suffer withdrawal symptoms if they attempt to stop.
Even the onset of a smoking-related illnes is not always sufficient to
enable heavy smokers to quit.

6. Deductive and Inductive Reasoning
Scientists use two basic methods to move from evidence to a conclusion:
deductive reasoning and inductive reasoning. Deductive reasoning moves from
a general premise or assumption to spesific conclusion. For example :
All metals are good condutors of electricity.
Zinc is a metal.
Therefore, zinc is a good conductor of electricity.

7. In contrast, inductive reasoning move sfrom spesific observation to a
general conclusion. For example, if air is observed to expand or contrast to fill
any container, the assumption might be made that all gases behave this way. As a
matter of fact they do.
Deductive reasoning is always valid, that is, if it is properly stated and if the
premises are true, the conclusion will be true. The conclusion is contained in the
premises. By contrast, inductive reasoning can lead to false conclusion. That
would be a false assumption. Nevertheless, inductive reasoning can be very
valuable in alerting the scientist to potential principles that must be then be
tested before they can be accepted.

8. Example
• when a block slides over a rough surface, the mechanical energy lost because
of friction is transformed into internal energy that is stored temporarily
inside the block and inside the surface, as evidenced by a measurable increase
in the temperature of both block and surface.
• We have evidence of the fact that the gravitational force acting on an object
is directly proportional to its mass from our observations of falling objects .
• The changes in internal energy in these examples are evidenced by
corresponding changes in the temperature of the gas.

9. • If the charged metal ball is now lowered into the interior of the charged hollow
conductor, it exhibits no evidence of an electric force.
• When the magnetization cycle is repeated, dissipative processes within the material
due to realignment of the domains result in a transformation of magnetic energy
into internal energy, which is evidenced by an increase in the temperature of the
substance.
• The earth is round. A person traveling directly east from the equator will eventually
return to the starting place
• A bell rung in a vacuum makes no sound. Sound is only produced when there are
molecules to transmit it.

10. • If a bottle of perfume is left open in a closed room, the smell will eventually
spread all over the room. The molecules of gas spread, or diffuse , to fill the
entire area.