Check for the pair English-Catalan (apertium-en-ca), the name of the 118 chemical elements that are not present in either English or Catalan, or both. Create a page on the wiki of Apertium (http://wiki.apertium.org/wiki/Main_Page).

Then for each missing elements, indicate:
- the name
- the atomic number
- if missing in English
- if missing in Catalan

Here are two links that can help you

http://en.wikipedia.org/wiki/Chemical_element
http://ca.wikipedia.org/wiki/Element_qu%C3%ADmic

You can use the online interface to test the missing words http://www.apertium.org/index.php?id=translatetext missing words are preceded by an asterix * (do not forget to check that option)