The following Language Log post by Victor Mair analyzes the Chinese characters for the Periodic elements. If you look at the picture, you can see how radicals (e.g. 气 for gas/vapor and 金 for gold/metal) combine with other elements to create new characters. As Mair points out, only a few common elements (e.g. silver, lead, mercury) had characters in common usage. Even the pronunciation for newer elements are adaptations of the Western element code (e.g. Sodium (Na) = nà)
This is as good an example as I’ve seen of how Chinese writing and phonology works with new terms.
Some Gas Elements (气)
Hydrogen (H) qīng
氫:氢
Helium (He) hài
氦:氦
Xenon (Xe) xiān
氙:氙
Older Names
Silver (Ag) yín
銀:银
Gold (Au) jīn
金:金
Unicode comes up again because newer element names have not necessarily been incorporated into different fonts or even into the Unicode standard.