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    Rb

    Rubidium

    Alkali Metal

    Atomic Number: 37 • Atomic Mass: 85.4680 u • Period: 5 • Group: 1

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹
    Phase: Solid
    Electronegativity: 0.82
    Krypton (Kr)Strontium (Sr)
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    Occurrence

    Rubidium is found in various natural sources, including minerals, rocks, and the Earth's crust.

    • Present in Earth's crust at about 90 ppm
    • Never found as free metal due to high reactivity
    • Found in minerals such as lepidolite, pollucite, and carnallite
    • Small amounts present in seawater
    • Trace element in some plants like tea, coffee, and tobacco