Why is it better to use the same cuvette for the blank and for the test samples?

School health education programs increasingly are partnering with community members and organizations on educational campaigns that not only benefit students but also the community at large. Discover strategies schools can use to improve their health education programs through partnerships with community stakeholders at the local and national levels.

Compare independent vs. dependent variables in science experiments. Explore both independent and dependent variable examples to understand how they work.

Well-written reporting is crucial to representing scientific investigations by expressing the goals and features of the study efficiently and accurately. Learn about the different parts of written scientific reports, explore where to put specific information, and understand the importance of conciseness to avoid repetition.

Learn about the responding variable definition and what it is. Examine responding variable examples. Learn how scientists use responding variables in experiments.

Learn what the scientific method is used for. Discover the history and steps of the scientific method in order, and study examples of the scientific method.

Dependent variables are one of three types of variables used in scientific experiments. Learn about the difference between dependent, independent, and control variables, and see how variables interact in an example of an experiment.

Discover how to design an experiment to find answers to scientific questions. Learn about the purpose of experiments, how they are part of the scientific method, types of variables and constants, and the steps to constructing a quality experiment.

The formation of stars results in a nuclear fusion that will continue to generate energy until the star burns out. Learn about nuclear fusion, the balance of forces during fusion, and understand how nuclear fusion cannot begin in a star until a specific internal temperature is reached.

Discover the steps of the scientific method - observation, question, hypothesis, experiment, and conclusion. Learn the definition of scientific observation and see examples. Understand how scientists make observations and why observations are important to science.

A measurement quantifies the physical characteristics of an object, such as its weight or length. Learn how to perform basic operations with measurements. Understand that measurements are like variables, and explore adding, subtracting, multiplying, and dividing them.

When using the metric system, it is helpful to know how to convert units from other systems. In this lesson, explore the metric system, how to set up a conversion, and how to calculate those units, with some additional practice.

Learn what variables and controls are in science experiments. Study the scientific method, control examples, and variable examples and see how they work.

Learn about constants in science and their role in scientific experiments. Explore the relationship between independent variables, dependent variables, and constants. Finally, discover how constants in an experiment help with validity.

Populations can be examined from an ecological perspective, exploring their dynamics that show similarities between human and animal groups. Learn the concepts of stability, fluctuation, immigration & emigration, and metapopulations in ecology.

Careful planning is a critical first step in the process of designing an experiment. Learn how to design an experiment, choose the correct tools, and analyze data so you can properly and efficiently complete an experiment.

The 118 known elements of the Earth create matter and cannot be broken down further chemically. Explore examples of elements, including the lightest elements, elements found in organic compounds, and elements that are metals or metalloids.