Pb
Lead is a dense, toxic heavy metal used since ancient times despite known health hazards.
Physical Properties
| Atomic Mass | 207.2 u |
| Density | 11.342 g/cm³ |
| Melting Point | 600.61 K |
| Boiling Point | 2022.0 K |
| Appearance | Bluish-gray metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 2.33 (Pauling) |
| 1st Ionization Energy | 715.6 kJ/mol |
| Electron Affinity | 35.1 kJ/mol |
| Oxidation States | -4, +2, +4 |
Atomic Properties
| Electron Configuration | [Xe] 4f14 5d10 6s2 6p2 |
| Atomic Radius | 175.0 pm |
| Covalent Radius | 146.0 pm |
| Van der Waals Radius | 202.0 pm |
Discovery
| Discovered By | Known since antiquity |
| Location | Various (Middle East) |
| Named After | Anglo-Saxon 'lead'; symbol Pb from Latin 'plumbum' |
About Lead
Lead is a heavy, soft, malleable metal used for over 6,000 years. It is toxic, causing nervous system damage. Removing lead from gasoline and paint has been a major public health achievement.
Uses & Applications
Lead-acid batteries, radiation shielding, ammunition, and construction.
Fun Fact
Some historians believe widespread lead poisoning from water pipes contributed to the decline of the Roman Empire.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 206 | 0.241% | - | Yes |
| 207 | 0.221% | - | Yes |
| 208 | 0.524% | - | Yes |
Electron Configuration
[Xe] 4f14 5d10 6s2 6p2