Name: Astatine

Atomic Symbol and Mass Number: At [85]

Electron Configuration: [Xe] 4f   5d   6s   6p

Atomic Radii: 200 pm

Electron Affinity: 270.1 kJ mol‑1

Oxidation States: -1, +1, +3, +5, +7

Electronegativity Value: 2.2

Elemental Group: Nonmetal

Uses and Properties:

• Astatine is highly radioactive and is only available in tiny quantities.

• Its properties are inferred from its position in the periodic table and by studying its chemistry in extremely dilute solutions.

• Like the other halogens, astatine would be expected to form salts with metals such as sodium.

• Astatine can also react with hydrogen to form hydrogen astatide, which when dissolved in water, forms hydrostatic acid.

• Astatine-211 is sometimes used as a radioactive tracer and in cancer treatment. Like iodine, it is known to accumulate in the thyroid gland

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Lewis Diagram: