[Free Registration/Login may be required to access all resource tools.] Students explore the history of the periodic table, and explain how the periodic table was originally organized, compared to the arrangement of the modern periodic...

Information about the element, Calcium, atomic number 20. Covers physical and atomic properties, sources, its role in geochemical cycles, how abundant it is on the Earth, its isotopes, some compounds of calcium, and its importance to...

Information about the synthetic, radioactive element, Mendelevium, atomic number 101. Covers its discovery, physical and atomic properties, and details about permissible exposure.

Information about the radioactive element, Uranium, atomic number 92. Describes its history, physical and atomic properties, how abundant it is on the Earth, and permissible exposure limits. Also discusses sources, uses, isotopes,...

Information about the metallic element, Rhenium, atomic number 75. Covers its physical and atomic properties, how abundant it is on the Earth, sources, uses, and potential substitutes.

Information about the radioactive element, Radon, atomic number 86. Covers physical properties, atomic properties, how abundant it is on the Earth, details about its impact on human health, and about how it can be monitored.

Information about the radioactive element, Radium, atomic number 88. Covers physical and atomic properties, how abundant it is on the Earth, and permissible exposure limits.

Information about the metallic element, Gallium, atomic number 31. Covers its discovery, its physical and atomic properties, sources, uses, how abundant it is on the Earth, and permissible exposure limits.

Information about the semi-metallic element, Boron, atomic number 5. Covers physical and atomic properties, how abundant it is on the Earth, sources, uses, and possible substitutes.

Information about the element Zirconium, atomic number 40. Covers history of its discovery, sources, physical properties, atomic properties, how abundant it is on the Earth, details about permissible exposure, uses, and possible...

Information about the element, Vanadium, atomic number 23. Covers its history, sources, physical and atomic properties, prevalence on the Earth, details about any health-related regulations, uses, and possible substitutes.

Information about the element, Silicon, atomic number 14. Covers physical properties, atomic properties, how abundant it is on the Earth, and details about health-related regulations. Also discusses sources of Silicon, and its many...

Information about the element, Oxygen, atomic number 8. Covers history, physical and atomic properties, abundance, and permissible exposure limits. Also discusses forms of oxygen, isotopes, sources, and uses.

Information about the element, Nitrogen, atomic number 14. Covers common chemical transformations, its physical properties, atomic properties, how abundant it is on the Earth, and details about health-related regulations. Also discusses...

Information about the metallic element, Molybdenum, atomic number 42. It is unique in having an extremely high melting point. Covers its discovery, its biological importance, its physical and atomic properties, how abundant it is on the...

Information about the element, Manganese, atomic number 25. Covers physical properties, atomic properties, how abundant it is on the Earth, details about health-related regulations, and its importance to human health. Also discusses...

Information about the metallic element, Lithium, atomic number 3. Covers its discovery, its physical and atomic properties, how abundant it is on the Earth, sources, uses, potential substitutes, and permissible exposure limits.

Information about the element, Iron, atomic number 26. Covers physical properties, atomic properties, how abundant it is on the Earth, and details about health-related regulations, and its importance to plant and to animal health. Also...

Information about the first element on the periodic table, Hydrogen, atomic number 1. Covers its history, sources, physical and atomic properties, places it occurs naturally on the Earth and in space, its many uses, and forms in which it...

Information about the element, Helium, atomic number 2. Covers its discovery, physical and atomic properties, how abundant it is on the Earth, its uses, possible substitutes, and permissible exposure limits.

Information about the element, Fluorine, atomic number 9. Covers physical and atomic properties, how abundant it is on the Earth, and permissible exposure limits. Also discusses uses, isotopes, and health concerns.

Information about the element, Copper, atomic number 29. Covers its history, sources, physical properties, atomic properties, how abundant it is on the Earth, details about permissible exposure, uses, and possible substitutes.

Information about the element, Bromine, atomic number 35. Covers physical properties, atomic properties, how abundant it is on the Earth, and details about health-related regulations. Discusses sources, uses, and substitutes.

Information about the element, Mercury, atomic number 80. Covers physical and atomic properties, where it is found, and health-related regulations. Also discusses its three main forms, uses for mercury, ways it spreads throughout the...