How the character is built
The 钅 radical marks this as a metal, and that is not a coincidence of this one character — it holds right across the table. Read the radical first and the element's state at room temperature is already settled. It is 金 (jīn) squeezed into the space beside another component — radicals change shape by position, which is why 金 is hard to spot until you know to look for 钅.
Where you actually meet it
镉污染 (gé wūrǎn) cadmium contamination
Where it sits among the 118
First isolated in 1817.
In living things
Cadmium sits directly beneath zinc in the table and behaves like a bad understudy — similar size, similar charge, happy to occupy zinc's places in proteins and unable to do zinc's work once there. The body responds by wrapping it in metallothionein, a small sulfur-rich protein, and filing the complex in the kidney, where its biological half-life is measured in decades rather than days. It also has an agricultural dimension: rice is unusually good at taking cadmium up from soil, particularly when a paddy is drained and the sediment turns oxidising, which is how metal from upstream mining at Toyama in Japan reached the diet of a farming population and produced one of the twentieth century's defining pollution cases.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
镉Cadmium in the dictionary →Others built the same way
Every one of these carries 钅, and every one is a metal.