Re: What is oxygen used for apart from us using it to breath?

Hi LaLa,

From our perspective, oxygen is most important because we require it to 
breathe.  We breathe in oxygen gas from the atmosphere, whereas plants 
breathe in carbon dioxide and release oxygen gas into the atmosphere.  This 
gaseous form of oxygen is diatomic, which means that there are two oxygen 
atoms in each molecule of oxygen gas (O2).  Ozone is the trivalent form of 
oxygen (O3), and ozone effectively shields us from ultraviolet radiation. 

Oxygen is not always found in the gaseous form, though.  It is actually the 
most abundant element in the Earth's crust, and plays in important role in 
mineral formation.  Multiple oxygen atoms will bond to elements that we 
find in the crust, such as iron or silicon.  Four oxygen atoms will bond to 
one silicon atom (SiO4), thereby forming a silica tetrahedron.  Numerous 
tetrahedra will combine with one another to form different rocks and 
minerals.  There's a neat mineral called mica that you might have seen 
before; it pulls apart in sheets and is fairly shiny.  Mica is just one 
mineral that contains silica tetrahedra that have combined in two 
dimensions to form those sheets.  Since the Earth is an oxidizing place, 
many minerals contain oxygen.

Remember that oxygen is also a key component of water.  Water is a 
requirement for life on Earth, and many chemical reactions take place in 
water environments.  In fact, many scientists think that the origin of life 
occurred in or around water.

If you would like more information, please write back.  I hope this helps.

Sarah Earley
CU Boulder