The lability of these chemicals makes them highly unstable at room temperature.

lability 是名词，由形容词 labile（不稳定的、易变的）加上名词后缀 -ity 构成，表示"不稳定性"或"易变性"的特性。词根 lab- 来自拉丁语 labi，意思是"滑动、不稳定"。