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
Helium (He) hài
Xenon (Xe) xiān
Silver (Ag) yín
Gold (Au) jīn
Unicode comes up again because newer element names have not necessarily been incorporated into different fonts or even into the Unicode standard.