Check your understanding of how to use the atomic number and the mass number to represent different isotopes. [9:43]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Take a look at the parts of an atom and learn about its properties.

An explanation of the sizes of different atoms due to the number of electrons that are orbiting in energy shells. [11:25]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Chemistry is the study of matter, and all matter is made up of atoms. We will learn about elements, atomic number and mass, isotopes, moles (chemistry moles, not the animal), and compounds.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Site provides the ABC's of nuclear science including radioactivity and gamma decay to fission and comic rays.

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Define matter and elements
Describe the interrelationship between protons, neutrons, and electrons
Compare the ways in which electrons can be donated or shared between atoms
Explain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

A video investigating the makeup of an atom. Learn that atoms are composed of protons, neutrons, and electrons. Understand that protons and neutrons determine the mass of an atom. Also, the atomic number gives you the number of protons in the nucleus. [21:05]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Here at Chem4Kids you can find some great information about the 4th element in the periodic table, "beryllium." Content focuses on beryllium's electrons, where you can find beryllium in nature, and how beryllium combines with other elements.

Here at Chem4Kids.com you can find some great information about the 5th element in the periodic table, "boron." Content focuses on boron's electrons, where you can find boron in nature and in the home, and how boron combines with other elements.

Click on the left navigation terms for some great information about the 6th element in the periodic table, "carbon." Content focuses on carbon's electrons, where you can find carbon in nature and in the home, and how carbon combines with other elements.

Here you can find some great information about the 9th element in the periodic table, "fluorine." Content focuses on fluorine's electrons, where you can find fluorine in nature and in the home, and how fluorine combines with other elements.

Here you can find lots of great information about helium. Learn about its electrons, where it exists in nature, and about the element itself!

Here you can find some great information about the 10th element in the periodic table, "neon." Content focuses on neon's electrons, where you can find neon in nature and in the home, and how neon combines with other elements.

Here you can find some great information about the 7th element in the periodic table, "nitrogen." Content focuses on nitrogen's electrons, where you can find nitrogen in nature and in the home, and how nitrogen combines with other elements.

Here you can find some great information about the 14th element in the periodic table, "silicon." Content focuses on silicon's electrons, where you can find silicon in nature and in the home, and how silicon combines with other elements.

Here at Chem4Kids you can find some great information about the 11th element in the periodic table, "sodium." Content focuses on sodium's electrons, where you can find sodium in nature and in the home, and how sodium combines with other elements.

Here you can find some great information about the 16th element in the periodic table, "sulfur." Content focuses on sulfur's electrons, where you can find sulfur in nature and in the home, and how sulfur combines with other elements.