Scientific Theories, Laws, and Hypotheses

• Statements or DESCRIPTIONS of WHAT we expect to happen, based on many observations and data collected.

• Only stat WHAT happens. NO attempt to explain why.

Scientific Law

• Broad EXPLANATIONS as to WHY something happens in the natural world

• support by many lines of evidence

• may be modified or changed with new evidence (always changing)

• theories NEVER become laws

Scientific Theory

Scientific Theory vs Scientific Law

• Both are widely accepted by the scientific community.

• Both are based on tested hypotheses.

• Both are supported by large amounts of data and evidence.

• Both could be shown to be wrong at some time if there are new data to suggest so.

How are theories and laws similar?

Match

Match the following statements as a scientific theory, scientific law, theory and law, or hypothesis. Discuss with your shoulder partner.

• Scientific Theory

• Scientific Law

• Hypothesis

• Scientific Theory & Law

Provides an explanation of cells and what we know about them.

Describes what nature does under certain conditions and will predict what will happen.

Something that can be tested

Are widely accepted by the scientific community

• Provides an explanation of cells and what we know about them.

• Describes what nature does under certain conditions and will predict what will happen.

• Something that can be tested

• Are widely accepted by the scientific community

Multiple Choice

Tamar is talking about evolution with a friend. The friend says, “It’s just a theory, so I don’t believe it. When they prove it and it becomes the law of evolution, then maybe I’ll change my mind.” Which of these possible replies best describes scientific principles or the work of scientists?

• Scientific theories do not become scientific laws; they are explanations for natural phenomena based on evidence.

• Science always finds the right answer; the answers that scientists and researchers discover never change.

• He should be wary of science because it is based on research and evidence, not bias and opinion.

• Scientists take each other at their word regarding experimental results, and the public should, too

Multiple Choice

Which of the following are well supported descriptions about what happens in nature, without attempting to explain why it happens?

• Scientific law

• Scientific Theory

• Both a scientific law and theory

• Scientific Observations

Multiple Choice

Joe tells Gabby his theory about why sea turtles nest on the beach instead of in the ocean. He says, “The turtle eggs would sink to the bottom of the ocean, and the baby turtle would drown. I know this because my uncle is a fisherman, and he told me this information. Gabby tells Joe that his theory is not scientific. Why does Joe’s idea not meet the requirements to be a scientific theory?

• Joe’s idea is already a scientific law.

• Joe’s idea is not supported by scientific evidence.

• Joe’s idea is a good guess that can be tested by experiments.

• Joe and his uncle are not scientists.

Multiple Choice

Scientific theories are based on

• general assumptions of how systems work.

• mathematical principles that can be proven true.

• large amounts of data collected over time.

• observations from within only one scientific discipline.

Theory of Continental Drift

Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed.

Multiple Choice

True or False: Scientific laws are typically a starting point when forming experiments.

• True

• False

Multiple Choice

What is not true about hypothesis

• IF….Then…” statement.

• Can be SUPPORTED or refuted

• a possible ANSWER

• all are true

Match

Match the following

• Scientific theory

• Scientific law

• Scientific model

• Hypothesis

Explains why or how something happens in nature

Describes what happens in nature

representation of a real event

a proposed explaination, starting point of an experiment

• Explains why or how something happens in nature

• Describes what happens in nature

• representation of a real event

• a proposed explaination, starting point of an experiment

Match

Match the following examples with the word

• Hypothesis

• Scientific Model

• Scientific Theory

• Scientific Law

If plants are grown in different colored light, then red light will grow the tallest.

plastic animal cell

germ theory

the law of motion

• If plants are grown in different colored light, then red light will grow the tallest.

• plastic animal cell

• germ theory

• the law of motion

Dalton's Atomic Theory

In 1808, this English schoolteacher proposed his own atomic theory that became widely accepted

Dalton’s Atomic Theory:

–All elements are made of tiny atoms.

–Atoms cannot be subdivided.

–Atoms of the same element are exactly alike.

–Atoms of different elements can join to form molecules.

Multiple Select

Can be changed if new information becomes available.

• Hypothesis

• Theory

• Law

Multiple Select

Widely accepted as true.

• Hypothesis

• Theory

• Law

The Law states matter is neither created nor destroyed as seen in this image. We started with 100g and when we broke apart the elements they STILL equal 100g of mass.

Multiple Select

Based on a single event or observation.

• Hypothesis

• Theory

• Law