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Basic Information
Name: Iodine
Symbol: I
Atomic Number: 53
Atomic Mass: 126.90447 amu
Melting Point: 113.5 °C (386.65 °K, 236.3 °F)
Boiling Point: 184.0 °C (457.15 °K, 363.2 °F)
Number of Protons/Electrons: 53
Number of Neutrons: 74
Classification: Halogen
Crystal Structure: Orthorhombic
Density @ 293 K: 4.93 g/cm3
Color: blackish
Atomic Structure
![[Bohr Model of Iodine]](Chemical Elements_com - Iodine (I)_files/b0053.gif) |
Number of Energy Levels: 5 First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 18 Fifth Energy Level: 7 |
Isotopes
| Isotope | Half Life |
| I-122 | 3.6 minutes |
| I-123 | 13.2 hours |
| I-124 | 4.2 days |
| I-125 | 60.1 days |
| I-126 | 13.0 days |
| I-127 | Stable |
| I-128 | 25.0 minutes |
| I-129 | 1.57E7 years |
| I-130 | 12.4 hours |
| I-131 | 8.0 days |
| I-132 | 2.3 hours |
| I-133 | 20.8 hours |
| I-134 | 52.6 minutes |
| I-135 | 6.6 hours |
| I-136 | 1.4 minutes |
Facts
Date of Discovery: 1811
Discoverer: Bernard Courtois
Name Origin: From the Greek word iôdes (violet)
Uses: required in humans
Obtained From: sodium and potassium compounds