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Astatine
উপাদান 85 · 209.98715 u
Astatine is the rarest naturally occurring element on Earth.
Physical Properties
| পদাৰ্থ | 209.98715 u |
| ঘনত্ব | 7.0 g/cm³ |
| Melting Point | 575.0 K |
| উত্তাপৰ বিন্দু | 610.0 K |
| আকৃতি | Likely metallic |
| State at Room Temp | Solid |
রাসায়নিক বৈশিষ্ট্যসমূহ
| ইলেকট্ৰোনেজেটিভিটি | 2.2 (Pauling) |
| 1- তম আইনাইজেশন শক্তি | 899.0 kJ/mol |
| ইলেকট্ৰন | 270.1 kJ/mol |
| Oxidation States | -1, +1, +3, +5, +7 |
প্ৰমাণপত্ৰৰ বৈশিষ্ট্য
| ইলেকট্ৰন | [Xe] 4f14 5d10 6s2 6p5 |
| পৰমাণু | 150.0 pm |
| কোভালেন্ট বেৰিয়াড | 150.0 pm |
| Van der Waals Radius | 202.0 pm |
ডিস্কভাৰী
| আবিষ্কাৰ কৰা হৈছে | Dale R. Corson, Kenneth Ross MacKenzie, Emilio Segre |
| আবিষ্কাৰৰ বছৰ | 1940 |
| অৱস্থান | Berkeley, California, USA |
| Named After | Greek 'astatos' meaning unstable |
বিষয়ে Astatine
Astatine is extremely rare, radioactive, and the heaviest known halogen. Less than 30 grams exist in Earth's crust at any time. It has never been seen in bulk.
Uses & Applications
Potential targeted cancer therapy (astatine-211), still experimental.
মজা কথা
Astatine has never been seen with the naked eye -- there is less than 30 grams in the entire Earth at any moment.
আইসোটোপ
| Mass Number | অভাৱ | হাফ-লাইফ | Stable |
| 209 | - | 5.41 hours | No |
| 210 | - | 8.1 hours | No |
| 211 | - | 7.214 hours | No |
ইলেকট্ৰন
[Xe] 4f14 5d10 6s2 6p5