You are only here temporarily①， but most of the atoms in your body are forever. We will deal with the tiny exception at the end of the answer， but let’s look at what happens to most of you：
　　You die. I’m very sorry.
　　You are either buried （embalmed② or not） or burned. There are a few other options， but they are rare.
　　If you are buried， your soft tissues③ are eventually eaten by bacteria④ and small organisms⑤. Much of that becomes carbon dioxide⑥， and the rest becomes the bodies of these organisms or their children.
　　If you are burned， your soft tissues are consumed by oxygen and mostly turned into carbon dioxide， water， and some nitrogen⑦ and sulfur oxides.
　　In both cases， though， the long term destination for those chemicals is the biosphere. You become food for other organisms.
　　Even your bones decay， albeit much more slowly. The calcium⑧ and phosphorus in bones will be incorporated into plants.
　　Some day the plants will be consumed by animals. Those animals will eventually die， be consumed， and cycle through the biosphere over and over again.
　　Eventually， tiny bits of you will end up in your great grandchildren’s corn fl akes or pork chop.
　　You really WILL live on - in the life on this planet.
　　Oh， the exception： radioactive elements. You don’t have many， but a few of your elements will decay into other elements before entering the biosphere. Radioactive potassium will turn into calcium. Tiny amounts of thorium and uranium will eventually become lead. With most of this decay， the new elements formed stay here on earth.
　　But with that last set， helium is formed. Earth’s gravity isn’t strong enough to hold helium， and so tiny bits of what once was you will fl oat off into space.
　　Some will be captured by the sun and Jupiter. A little will escape the solar system and drift off to the stars.
　　Your atoms have an exciting life after yours is over！
　　你在这个地球上只是暂时逗留，而你身体里大多数的原子则是永远。我会在文中最后的部分说一下那一小撮，现在先说说那些大多数：
　　你挂了，深表遗憾。
　　你抑或是被埋入土里（防腐处理，或者没有），抑或是焚烧成灰。可能还有其他的做法，但毕竟只是少数。
　　如果你被埋，身体里的软组织会被细菌和微生物吃掉，很多转化为二氧化碳，其他的部分会成为它们身体的一部分，或者是它们的孩子。
　　如果你被焚烧了，你体内的软组织会和氧气反应，变成二氧化碳、水和一些氮、硫氧化物。
　　就算是这两种情况，这些化学物质都会慢慢去到最后的目的地：生物圈。你将会成为其他生物的养料。
　　尽管很慢，你的骨头也终会被降解。骨头里的钙和磷会被植物吸收。
　　某一天，植物会被动物吃掉，这些动物最后也会死去，被腐蚀，原子们在生物圈中周而复始，长此以往。
　　最终，你的每一小部分或许会成为你外孙早餐里的玉米片或是午餐里的猪排肉。
　　你的確会在这颗星球上永远存在，在这些生命之中。
　　噢，差点忘了，有个例外是放射性元素。你身体里不会有很多，它们在进入生物圈之前会衰变成其他的元素。放射性的钾会变成钙。一丢丢的钍和铀会成为铅。因为有这种衰变，新的元素会形成，然后永久地在地球上安居。
　　但还有最后的一小部分，氦气会形成。地球的重力还不足以留住它们，这曾是你身体一部分的氦会飞入宇宙。
　　这些氦气可能会被太阳和木星捕捉，另外一小部分则会逃离太阳系，去往下一站星系。
　　话说，你走之后，你的原子们真的过得颇为精彩呢！