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Elements

• 201
• ChemicalElements.com: Iron
• Basic information, atomic structure, and isotopes.

• 202
• It's Elemental: Iron
• Basic physical and historical information.

• 203
• USGS Minerals Information: Iron
• Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).

• 204
• WebElements: Iron
• Extensive information on history, uses, occurrence, compounds, and properties of the element.

• 205
• Wikipedia: Iron
• Properties of the element, including its history, applications, and characteristics.

• 206
• Chemical Elements.com: Krypton
• Basic information, atomic structure, and table of isotopes.

• 207
• Especiál Gas Inc.: Krypton
• Numeric data, uses, and general information.

• 208
• It's Elemental: Krypton
• Basic physical and historical information.

• 209
• What Does the Element Krypton Look Like?
• Explanation with photographs.

• 210
• Wikipedia: Krypton
• Properties of the element, including its history, applications, and characteristics.

• 211
• ChemicalElements.com: Lanthanum
• Basic information, atomic structure, and isotopes.

• 212
• It's Elemental: Lanthanum
• Basic physical and historical information.

• 213
• Wikipedia: Lanthanum
• Properties of the element, including its history, applications, and characteristics.

• 214
• ChemicalElements.com: Lawrencium
• Basic information, atomic structure, and isotopes.

• 215
• It's Elemental: Lawrencium
• Basic physical and historical information.

• 216
• Wikipedia: Lawrencium
• Characteristics and history of the element.

• 217
• ChemicalElements.com: Lead
• Basic information, atomic structure, and isotopes table.

• 218
• It's Elemental: Lead
• Basic physical and historical information.

• 219
• USGS Minerals Information: Lead
• Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).

• 220
• Wikipedia: Lead
• Properties of the element, including its history, applications, and characteristics.