Cr
Chromium is a hard, lustrous transition metal valued for its mirror finish and corrosion resistance.
Physical Properties
| الكتلة الذرية | 51.996 u |
| الكثافة | 7.15 g/cm³ |
| Melting Point | 2180.0 K |
| نقطة الغليان | 2944.0 K |
| المظهر | Steely-gray, lustrous, hard metallic |
| State at Room Temp | Solid |
الخواص الكيميائية
| السالبية الكهربائية | 1.66 (Pauling) |
| طاقة التأين الأولى | 652.9 kJ/mol |
| القرب الإلكتروني | 65.2 kJ/mol |
| Oxidation States | +1, +2, +3, +4, +5, +6 |
الخصائص الذرية
| تشكيل الإلكترون | [Ar] 3d5 4s1 |
| نصف قطر الذرة | 128.0 pm |
| نصف قطر التكافؤ | 139.0 pm |
| Van der Waals Radius | 189.0 pm |
اكتشاف
| اكتشفها | Louis Nicolas Vauquelin |
| سنة الاكتشاف | 1797 |
| الموقع | Paris, France |
| Named After | Greek 'chroma' meaning color, due to its many colorful compounds |
عن Chromium
Chromium is a steely-gray, lustrous, hard metal that takes a high polish. It is remarkable for its resistance to tarnishing. It has an unusual electronic configuration with only one 4s electron due to the stability of a half-filled 3d shell.
Uses & Applications
Stainless steel, chrome plating, pigments, leather tanning, and catalysts.
حقيقة مضحكة
Chromium has an anomalous electron configuration -- it 'steals' an electron from 4s to give a half-filled 3d orbital.
النظائر
| Mass Number | الوفرة | نصف العمر | Stable |
| 50 | 0.04345% | - | Yes |
| 52 | 0.83789% | - | Yes |
| 53 | 0.09501% | - | Yes |
| 54 | 0.02365% | - | Yes |
تشكيل الإلكترون
[Ar] 3d5 4s1