manganese
錳 refers specifically to the metallic element manganese. It is a technical character with no extended abstract meanings.
錳 is a modern character created for the chemical element manganese. It combines the metal radical 金 with 孟, which likely contributes the sound モウ.
The left side 金 (metal) tells you it is a metal, and the right side 孟 (manganese sound) reinforces the specific element. Picture a shiny manganese ingot stamped with the character 孟.
For モウ, imagine a mow (as in mowing grass) sound: the manganese metal is so tough it can mow down other metals. Mow -> モウ.