铬 has the metal radical 钅 on the left, marking it as a metal element. The right side 各 (each) gives the pronunciation. Chromium's symbol Cr comes from Greek chroma (color) - it produces vivid colors in compounds.
Left metal radical - simplified left-side form of 金. Indexes 铬 firmly in the metals family. The Chinese names of nearly all metal elements were coined with this radical plus a phonetic that approximates the Western name's first syllable: 铁 iron, 铜 copper, 银 silver.
Right 各 supplies the sound - gè unchanged. Here the meaning doesn't carry; it is a pure phonetic chosen to spell the first syllable of 'chromium'. The same phonetic also gives 格 (pattern), 客 (guest), 落 (fall).
