Mercury vs Lead
Mercury is a metal (transition metal); Lead is a metal (post-transition metal).
The differences in plain English
- They share period 6, the same row, so their outer electrons are in the same shell but they differ in how many there are: Mercury has 2, Lead has 4.
- At room temperature Mercury is a liquid and Lead is a solid.
- Lead melts at 327 °C, Mercury at -39 °C.
- An atom of Lead is only slightly heavier than an atom of Mercury (207.21 u against 200.59 u).
- Mercury pulls electrons more strongly in a bond (electronegativity 2 against 1.87).
Side by side
| Mercury | Lead | |
|---|---|---|
| Atomic number | 80 | 82 |
| Symbol | Hg | Pb |
| Family | Transition metal | Post-transition metal |
| Group / period | 12 / 6 | 14 / 6 |
| State at room temperature | Liquid | Solid |
| Atomic mass | 200.592 u | 207.210 u |
| Density | 13.534 g/cm³ | 11.34 g/cm³ |
| Melting point | -39 °C | 327 °C |
| Boiling point | 357 °C | 1749 °C |
| Electronegativity | 2 | 1.87 |
| First ionisation energy | 1007.1 kJ/mol | 715.6 kJ/mol |
| Electron configuration | [Xe] 4f14 5d10 6s2 | [Xe] 4f14 5d10 6s2 6p2 |
| Discovered by | unknown, before 2000 BCE | Middle East |
Mercury
Tip a bottle of mercury and a bright silver liquid pours out, so heavy that a steel ball bearing, or even a lump of lead, floats on it. It is the only metal that stays liquid at ordinary temperatures, and its old English name, quicksilver, means living silver. Its symbol Hg comes from the Latin hydrargyrum, water-silver.
- Mercury is so dense that iron, lead and even a cannonball will float on it.
- The chemical symbol Hg comes from the Latin hydrargyrum, meaning water-silver.
Lead
Lead is a dull, bluish grey metal so soft you can scratch it with a fingernail and melt it over a camping stove. It was one of the first metals people ever smelted, and for most of history it seemed almost too useful: it kept rain off cathedrals, carried water through Roman cities, printed books and stopped engines knocking.
- Lead pollution from Roman smelters can be measured in Greenland ice cores laid down two thousand years ago.
- The lead in pencils has never been lead; it is graphite, mistaken for a lead ore when it was first mined in Cumbria.
Colour the bubbles by density or melting point and the difference jumps out.
More comparisons
Data from Periodic-Table-JSON (CC BY-SA); temperatures rounded to the nearest degree. Written by Anthony.