argon

We could use argon ion.

我们可以用氩离子。

Others decay more slowly, like some cesium, iodine, strontium, and argon.

剩下的一些延迟消退的很慢，比如铯、碘、锶和氩。

The atmosphere is roughly 78 percent nitrogen, 21 percent oxygen, with trace amounts of water, argon, carbon dioxide and other gases.

地球大气含有大约78％的氮气、21％的氧气和痕量的水蒸气、氩气和二氧化碳等其它气体。