An ion is a tiny piece of matter — an atom, or a small group of atoms stuck together — that is not electrically quiet. An ordinary atom has the same number of negative bits (electrons) and positive bits (protons), so it does not pull or push. If it loses an electron, it becomes a positive ion; if it gains one, it becomes a negative ion.

An ion is a tiny piece of matter離子是很小的一塊物質—— an atom, or a small group of atoms stuck together可能是一個原子，或黏在一起的一小群原子—— that is not electrically quiet而且它在電性上「不安靜」。 An ordinary atom has the same number of negative bits (electrons) and positive bits (protons)一般的原子裡負電的部分（電子）和正電的部分（質子）數量一樣多， so it does not pull or push所以不會吸引或排斥。 If it loses an electron如果它失去一個電子， it becomes a positive ion就變成正離子； if it gains one如果得到一個電子， it becomes a negative ion就變成負離子。

Salt in water breaks into ions, and that is why the water can carry electricity. Chemists use the word all the time, in a careful way. Shops also talk about “negative ions” in the air as if they were a kind of freshness; that is the same science word, stretched for selling.

Salt in water breaks into ions鹽在水裡會分解成離子， and that is why the water can carry electricity這就是為什麼水可以導電。 Chemists use the word all the time化學家一直都在用這個詞， in a careful way而且用得很嚴謹。 Shops also talk about "negative ions" in the air商家也會講空氣裡的「負離子」， as if they were a kind of freshness好像那是一種清新感， that is the same science word, stretched for selling那其實是同一個科學詞，被拿來用在行銷上。

The name was made in 1834 by William Whewell for the scientist Michael Faraday. Whewell took it from a Greek word meaning “going,” because Faraday pictured these charged bits as going toward one pole or the other.

The name was made in 1834 by William Whewell for the scientist Michael Faraday這個名字是1834年William Whewell為科學家Michael Faraday創造的。 Whewell took it from a Greek word meaning "going,"Whewell是從一個意思是「前進」的希臘字取來的， because Faraday pictured these charged bits as going toward one pole or the other因為Faraday想像這些帶電的小東西是朝著某一極移動。