Scientific Theories and Laws

Scientific theories do not change once they have been written down.

• True

• False

A scientific ____________ is a statement that describes what always happens under certain conditions in nature.

• law

• theory

• method

• variable

Tags

NGSS.MS-PS1-5

NGSS.MS-PS2-4

A scientific theory...

• is based on lots of evidence

• is not valid

• is not reliable

• has not been tested many times

Tags

NGSS.HS-LS4-1

NGSS.HS-LS4-2

Scientists __________________ test scientific theories.

• constantly

• rarely

• never

Attempts to explain why something happens Explain how a natural phenomenon works based on available evidence.

• Law

• Theory

• Hypothesis

Tags

NGSS.MS-LS1-4

NGSS.MS-LS4-4

True/False: “If a hypothesis is supported, it becomes a theory. If a theory is proven it becomes a law”.

• True

• False

True/False. A scientific theory can change with new evidence and cannot change into a law.

• True

• False

The following statements apply to both theory and law: Based on evidence. Cannot change into each other. Widely accepted by the majority of scientists in the given field of study

• True

• False

The development of microscopes allowed scientists to investigate living things in greater detail. Through many investigations, scientists found evidence that all living things are made of one or more basic units that divide to form new units. Scientists used their evidence to explain the relationship between these “building blocks of life” and the organisms to which they belong. What are these explanations called?

• Cell theory

• Germ theory

• Law of biogenesis

• Law of mitosis

Atomic theory, which describes the atoms that make up matter, has been explored for centuries. Scientists in ancient Greece first proposed that matter was made of units called atoms. For many years, scientists thought atoms were solid and could not be divided. Then, in the nineteenth century, scientists began to discover the particles that make up atoms. Modern techniques have allowed scientists to split atoms into increasingly smaller particles. Which of the following statements about theories is supported by the history of the atomic theory?

• If new evidence contradicts earlier theories, it is a result of an experimental error.

• Experiments with modern equipment cannot be used to support earlier theories.

• A theory is discarded when new evidence contradicts a part of the theory.

• Theories can change in response to new evidence.