素 element

SOME ONE has elements of poop in SOME UNDERPANTS of theirs.

The elements (copper, silver, iron, etc.) are like the strings which bind together molecules, therefore the elements are the masters of the physical world.

the best! ★★★☆☆ FP
素 (element) + 晴 (weather get good now) = 素晴らしい (the best!)

the best! Usually used about art or theatrical performances.
A way to remember the pronunciation is that the ON-yomi of 素 is 'SU', while the KUN-yomi of 晴 is 'hareru'. . . which, because 晴 is the second kanji in the word, the 'ha' turns to 'BA'.
So maybe KUN-ON is a more accurate tag, but even then it's hard to remember, so FP it is!

raw material ★★☆☆☆
素 (element) + 材 (raw materials) = 素材 (raw material)

raw material - both literally and figuratively (as in, the raw data that you base your essay or report or novel on) ("I'm working on materal for my novel!")

oxygen. ☆☆☆☆☆ FR
酸 (sour) + 素 (element) = 酸素 (oxygen.)

oxygen - which is kind of a Fucked Roots if you think about it - "sour element?" What have they got against oxygen?!? What SHOULD we be breathing?

carbon dioxide ☆☆☆☆☆
二 (two) + 酸 (sour) + 化 (transform) + 炭 (carbon) + 素 (element) = 二酸化 炭素 (carbon dioxide)