Lithium is a soft, silver-white metal, and it is the lightest metal we know. It is a chemical element; its symbol is Li. In real life you almost never see a lump of it, because it reacts eagerly — especially with water — so it is stored with care.

Lithium鋰 is a soft, silver-white metal是一種柔軟的銀白色金屬，and it is而且是 the lightest metal we know我們已知最輕的金屬。It is a chemical element它是一種化學元素；its symbol is符號是 Li鋰(Li)。In real life在現實生活中 you almost never see你幾乎不會看到 a lump of it一塊鋰，because因為 it reacts eagerly它反應非常活躍——especially with water尤其是碰到水——so it is stored with care所以保存時要非常小心。

Students meet the word for two everyday reasons. First, batteries: phones, laptops, earbuds, and electric cars commonly use lithium-ion batteries. Second, medicine: doctors sometimes prescribe a lithium salt for certain mood conditions, and then people say “lithium” for the drug, not a piece of metal.

Students學生 meet the word碰到這個字 for two everyday reasons是因為兩個日常的理由。First第一，batteries電池方面：phones, laptops, earbuds, and electric cars手機、筆電、耳機和電動車 commonly use常會用 lithium-ion batteries鋰離子電池。Second第二，medicine醫療方面：doctors醫生 sometimes prescribe有時會開 a lithium salt鋰鹽 for certain mood conditions用來治療某些情緒方面的疾病，and then people say而這時候人們會說"lithium"（鋰） for the drug是指這種藥，not a piece of metal而不是一塊金屬。

Those two uses share the same element, but they are not the same object. Chemists named it from the Greek word for stone, because it was first found locked inside a mineral, not lying about as pure metal.

Those two uses這兩種用法 share the same element都是同一個元素，but they are not但它們不是 the same object同一個東西。Chemists化學家 named it from the Greek word為它命名時用了希臘文裡 for stone表示「石頭」的字，because因為 it was first found它最初是被發現 locked inside a mineral鎖在一種礦物裡面，not lying about as pure metal而不是以純金屬的樣子散落在外面。