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.
Phonetic 合; the reading hā is otherwise almost only met in 哈.
This character is used for the element and little else — you are unlikely to meet it outside a chemistry classroom.
The element itself
Hafnium went unfound until 1923, absurdly late for an element that is not rare, and it had been hiding in plain sight the whole time: it sits inside essentially every zircon crystal, at a percent or two, because hafnium and zirconium are almost impossible to tell apart chemically. That similarity became suddenly urgent when nuclear reactors were designed, because zirconium is nearly transparent to neutrons and hafnium devours them — so the fuel cladding needs one and the control rods need the other, and separating a pair of twins to that standard became an industry in itself.
Where it sits among the 118
First isolated in 1922.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
铪Hafnium in the dictionary →Others built the same way
Every one of these carries 钅, and every one is a metal.