Fr
Francium
উপাদান 87 · 223.01973 u
Francium is the most unstable naturally occurring element with a half-life of only 22 minutes.
Physical Properties
| পদাৰ্থ | 223.01973 u |
| ঘনত্ব | 1.87 g/cm³ |
| Melting Point | 300.0 K |
| উত্তাপৰ বিন্দু | 950.0 K |
| আকৃতি | Likely silvery metallic |
| State at Room Temp | Solid |
রাসায়নিক বৈশিষ্ট্যসমূহ
| ইলেকট্ৰোনেজেটিভিটি | 0.7 (Pauling) |
| 1- তম আইনাইজেশন শক্তি | 380.0 kJ/mol |
| ইলেকট্ৰন | 46.89 kJ/mol |
| Oxidation States | +1 |
প্ৰমাণপত্ৰৰ বৈশিষ্ট্য
| ইলেকট্ৰন | [Rn] 7s1 |
| পৰমাণু | 260.0 pm |
| কোভালেন্ট বেৰিয়াড | 260.0 pm |
| Van der Waals Radius | 348.0 pm |
ডিস্কভাৰী
| আবিষ্কাৰ কৰা হৈছে | Marguerite Perey |
| আবিষ্কাৰৰ বছৰ | 1939 |
| অৱস্থান | Paris, France |
| Named After | Named after France |
বিষয়ে Francium
Francium is an extremely radioactive alkali metal. Its longest-lived isotope has a half-life of only 22 minutes. It has never been produced in visible quantities and was the last element discovered in nature.
Uses & Applications
No commercial applications. Used only in basic spectroscopy research.
মজা কথা
At most about 30 grams of francium exist in the entire Earth's crust, and the largest amount collected was about 300,000 atoms.
আইসোটোপ
| Mass Number | অভাৱ | হাফ-লাইফ | Stable |
| 221 | - | 4.9 minutes | No |
| 223 | - | 22.0 minutes | No |
ইলেকট্ৰন
[Rn] 7s1