• 6-8: 4D/M1a. All matter is made up of atoms, which are far too small to see directly through a microscope.
• 6-8: 4D/M1b. The atoms of any element are like other atoms of the same element, but are different from the atoms of other elements.
• 6-8: 4D/M5. Chemical elements are those substances that do not break down during normal laboratory reactions involving such treatments as heating, exposure to electric current, or reaction with acids. All substances from living and nonliving things can be broken down to a set of about 100 elements, but since most elements tend to combine with others, few elements are found in their pure form.
• 6-8: 4D/M6a. There are groups of elements that have similar properties, including highly reactive metals, less-reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon).
• 6-8: 4D/M6b. An important kind of reaction between substances involves the combination of oxygen with something else—as in burning or rusting.
• 6-8: 4D/M6c. Carbon and hydrogen are common elements of living matter.
• 6-8: 4D/M10. A substance has characteristic properties such as density, a boiling point, and solubility, all of which are independent of the amount of the substance and can be used to identify it.
• 6-8: 4D/M11. Substances react chemically in characteristic ways with other substances to form new substances with different characteristic properties.

Interactively explore how the elements come together to produce the complex diversity of materials that make up the substances in our world. Click on "Human Body" to see which elements are most abundant in our bodies; click "Pyrotechnics" to see how experts combine certain elements to create fireworks; and learn which elements have the most extreme properties on the periodic table.

• Physical Sciences K-8 Elements and the Periodic Table Unit
• Physics First Elements and the Periodic Table Unit
• Conceptual Physics Elements and the Periodic Table Unit