A chemical compound — a salt or ester of sulfuric acid; that is, what you get when sulfuric acid reacts with something else and gives up its hydrogen. Common ones a student may actually meet: copper sulfate (the bright blue crystals in school science), magnesium sulfate (Epsom salts, used in baths), calcium sulfate (plaster).

that is也就是說 when sulfuric acid reacts with something else and gives up its hydrogen當硫酸和其他物質反應、放掉氫的時候 what you get所得到的 a chemical compound就是一種化合物 a salt or ester of sulfuric acid也就是硫酸的鹽或酯。Common ones a student may actually meet學生實際上可能會遇到的常見例子包括 copper sulfate硫酸銅（the bright blue crystals in school science學校科學課上那種鮮藍色的結晶）、magnesium sulfate硫酸鎂（Epsom salts瀉鹽，used in baths用來泡澡）、calcium sulfate硫酸鈣（plaster石膏）。

This spelling with an f is the American one; British writing uses sulphate. The two are the same word, said the same way, and the difference is only which side of the Atlantic — though it is worth knowing that the international body of chemists (IUPAC) chose the f spelling as the official one, so scientific journals worldwide, British ones included, now write sulfate. That means the 'American spelling' label is true for ordinary writing but not really for science any more.

This spelling with an f這個用 f 拼的寫法 is美式 the American one拼法；British writing英式寫法 uses用的則是 sulphate。The two are the same word兩者其實是同一個字，said the same way唸法也一樣，and the difference is only就只差在 which side of the Atlantic大西洋的哪一邊──though it is worth knowing不過值得知道的是 that the international body of chemists (IUPAC)國際化學家組織（IUPAC） chose選定了 the f spelling as the official one f 這個拼法為正式寫法，so scientific journals worldwide, British ones included, now write sulfate所以現在全世界的科學期刊，包括英國的期刊在內，都寫成 sulfate。That means這就表示 the 'American spelling' label「美式拼法」這個標籤 is true for ordinary writing but not really for science any more在日常書寫上是對的，但在科學上其實已經不太適用了。

You will also see it outside the lab: shampoo bottles say 'sulfate-free', meaning without the strong detergents (like sodium lauryl sulfate) that make foam and can dry out hair.

You will also see it outside the lab在實驗室之外你也會看到這個字：shampoo bottles say洗髮精瓶身會寫 'sulfate-free'「不含硫酸鹽」，meaning意思是 without the strong detergents不含那些強力清潔劑（like sodium lauryl sulfate像月桂硫酸鈉） that make foam and can dry out hair會起泡、也可能讓頭髮乾澀的成分。

There is also a rare technical verb, to sulfate, used about a car battery going bad as sulfate builds up on its plates.

There is also還有 a rare technical verb一個少見的專業動詞, to sulfate（sulfate 當動詞用）, used about用來說 a car battery going bad汽車電瓶故障 as sulfate builds up on its plates因為硫酸鹽堆積在電瓶板上的情況。