Tl
Thallium
العنصر 81 · 204.38 u
Thallium is a highly toxic post-transition metal once used as rat poison.
Physical Properties
| الكتلة الذرية | 204.38 u |
| الكثافة | 11.85 g/cm³ |
| Melting Point | 577.0 K |
| نقطة الغليان | 1746.0 K |
| المظهر | Silvery-white metallic |
| State at Room Temp | Solid |
الخواص الكيميائية
| السالبية الكهربائية | 1.62 (Pauling) |
| طاقة التأين الأولى | 589.4 kJ/mol |
| القرب الإلكتروني | 19.2 kJ/mol |
| Oxidation States | +1, +3 |
الخصائص الذرية
| تشكيل الإلكترون | [Xe] 4f14 5d10 6s2 6p1 |
| نصف قطر الذرة | 170.0 pm |
| نصف قطر التكافؤ | 145.0 pm |
| Van der Waals Radius | 196.0 pm |
اكتشاف
| اكتشفها | William Crookes |
| سنة الاكتشاف | 1861 |
| الموقع | London, England |
| Named After | Greek 'thallos' meaning green shoot, from its bright green spectral line |
عن Thallium
Thallium is a soft, silvery-white metal that is extremely toxic. It was historically used as a murder weapon due to its tastelessness and was banned as rat poison in many countries.
Uses & Applications
Semiconductor devices, infrared optics, medical imaging, and specialized glass.
حقيقة مضحكة
Thallium was the 'poisoner's poison' -- tasteless, odorless, and its symptoms mimicked common illnesses.
النظائر
| Mass Number | الوفرة | نصف العمر | Stable |
| 203 | 0.2952% | - | Yes |
| 205 | 0.7048% | - | Yes |
تشكيل الإلكترون
[Xe] 4f14 5d10 6s2 6p1