Science Experiments and the Scientific Method

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Questions and Answers

What is the primary purpose of scientific experiments?

To develop new drugs and treatments

To study the impact of human actions on ecosystems

To figure out how natural systems work (correct)

To understand how to preserve the world we live in

What is a variable in a science experiment?

The changing part of an experiment that can have many different possible values (correct)

A fixed part of an experiment that remains constant

A tool used to collect data in an experiment

A hypothesis that is tested in an experiment

What is the first step in the scientific method?

Conducting an experiment

Analyzing data

Formulating a hypothesis

Observation of natural phenomenon or researching existing knowledge (correct)

What happens at the end of the scientific method?

The hypothesis is accepted or rejected and revised Signup and view all the answers

Why are scientific experiments essential?

They are the foundation of science and essential for learning how the world works Signup and view all the answers

What is the role of a hypothesis in the scientific method?

It is a educated guess that is tested through experimentation Signup and view all the answers

What is the outcome of using the scientific method?

All of the above Signup and view all the answers

What is the purpose of changing only one variable at a time in an experiment?

To ensure that the results of the experiment are due to the independent variable alone Signup and view all the answers

What is the independent variable in an experiment where a scientist wants to study the effect of water on plant growth?

The amount of water given to the plants Signup and view all the answers

What is the purpose of controlled variables in an experiment?

To ensure that the results of the experiment are due to the independent variable alone Signup and view all the answers

What is the dependent variable in an experiment where a scientist wants to learn about a new compound that will affect cell growth in culture?

The number of cells Signup and view all the answers

What is the purpose of a control in a scientific experiment?

To provide a baseline for comparison of the dependent variable Signup and view all the answers

What is the independent variable in an experiment where a new drug is in development to treat osteoporosis?

The presence of the drug Signup and view all the answers

What is the purpose of a placebo in an experiment?

To provide a baseline for comparison of the dependent variable Signup and view all the answers

What is the dependent variable in an experiment where a scientist wants to study the effect of water on plant growth?

The height of the plants as measured at specific intervals Signup and view all the answers

Study Notes

Science Experiments

A science experiment is a process that uses a structured way of testing hypotheses to uncover natural phenomena.
Scientific experiments help scientists figure out how natural systems work.
Experiments are the foundation of science and are essential for learning how the world works.

The Scientific Method

The scientific method is a series of steps that include observation, measurements, experimentation, and analysis.
The scientific method starts with observation of natural phenomenon or researching the existing knowledge on a topic.
A scientist creates a question that will be answered through their application of the scientific method.
A hypothesis is created as an educated guess as to what will happen in the experiment.
The scientist conducts an experiment and collects data to analyze.
The hypothesis is accepted or rejected and revised, and the process begins again to ask a new question based on the data gathered.

Variables in Science Experiments

A variable is the changing part of an experiment and can have many different possible values.
The variable that is being changed in an experiment is called the independent variable.
The experiment quality that the scientist measures as the outcome of the experiment is called the dependent variable.
Controlled variables are the facets of the experiment that are kept the same to ensure that the results of the experiment are due to the independent variable alone.

Examples of Variables

Example: A scientist wants to study the effect of water on plant growth.
- The amount of water given to the plants is the independent variable.
- The height of the plants as measured at specific intervals is the dependent variable.
- The controlled variables are the other things the plants might need, such as sunlight, temperature, and soil composition.
Example: A scientist wants to learn about a new compound that will affect cell growth in culture.
- The presence of the drug is the independent variable.
- The number of cells is the dependent variable.
- The controlled variables are things like the temperature the cells are kept at, the type of conditions they are grown in, and the amount of media they get.

Controls in Science Experiments

A control in a scientific experiment is something used as a standard for comparison to check the results of an experiment.
Controls are important because they provide a baseline for comparison of the dependent variable in the experiment.
Example: A new drug is in development to treat osteoporosis.
- The independent variable is the presence of the drug.
- Participants in both groups were instructed to have the same diet and exercise regimen, the controlled variables.
- The dependent variable, or the outcome of the experiment is the bone density of participants after one month.
- The control in this experiment is the group of participants that received the placebo.