二氧化碳

二 = 一 : Mnemonic symbol: a capacitor, because the two strokes remind me of the symbol in electrical drawings. Albert Einstein (Ø) is experimenting with a capacitor (二) in the space station's bathroom (Ø4). He finds that it's uncomfortable to discharge a capacitor using two flutes (一).

氧 = 气 + 羊 : Maud Younger (y) gave the sheep (羊) a balloon (气) inside of the anglepod (ang3), but unfortunately it doesn't float because it is filled with oxygen (氧).

化 = 亻 + 匕 : Helga Horse and Rosa Luxemburg conduct an experiment in the ashram's bathroom. Using a transformer, they melt a ladle.

碳 = 炭 + 石 : Tecumseh (t) further processes the charcoal (炭) he made in the anthill's bathroom (an4) into pure carbon (碳) by crushing the charcoal (炭) into its elements and exerting extreme pressure with a rock (石).