Where Can I Find Elemental Mods For My Weapon?

[(PSN)Jackiplier]

I really need to know faction weaknesses and where I can find mods for those weaknesses

[SleepyPip]

Wiki or Codex

[NovusNova]

Wiki or Codex

 

http://warframe.wikia.com/wiki/WARFRAME_Wiki

[f-e-a-r-s]

You have to scan enemies enough first in order to know their weaknesses/resistances in the codex though, you can get codex scanners from the marketplace under the 'Gear' section.

[Quasar-Sandwich]

I really need to know faction weaknesses and where I can find mods for those weaknesses

First, you try to find the information yourself instead of posting to the general discussion forum. Next, you act on the information you found yourself.