yuánzì Chinese characters of the chemical elements
白

白 bái

“white; pure, unblemished; bright”

On its own, an ordinary character; Cantonese baak6. Readings and gloss from the Unicode Unihan database.

Carries Platinum

钅 metal → solid metal
+
白 bái
=
铂 bó · Pt 78

Not a plain transliteration: the component was chosen for its meaning, or the name is older than the system.

The reading drifted: the component is read bái, the element bó.