yuánzì Chinese characters of the chemical elements
雷

雷 léi

“thunder”

On its own, an ordinary character; Cantonese leoi4. Readings and gloss from the Unicode Unihan database.

Carries Radium

钅 metal → solid metal
+
雷 léi
=
镭 léi · Ra 88

Transliterates syllable 1 of ra·dium: radium → léi.

The element keeps the component’s reading exactly.