[e3xu]

In practice, the Chinese language typically represents concepts in 2 or 4 ideograph segments. Not every possible combination is in regular usage, but the number of potential linguistic "words" is closer in order of magnitude to the 10000 choose 2 binomial coefficient, i.e. 49995000.

[mc32]

So basically when they don't have a word for a new concept they devise a new one made of existing radical+ideograph+ideograph.