Science question: What causes elements to change into diffrerent elements?

[Taverner]

For example - when a cow eats grass (mostly carbon, hydrogen and oxygen), and that said cow digests the grass, the cow releases a new element not in the grass - methane - into the air.

How do those elements, which previously may have been carbon, hydrogen and oxygen or whatever then become methane, a new element?

Forgive any mistakes I may have made - I'm not a science guy.

[ThomCat]

1. They elements don't change.

Just the combination of those elements into molecules. The molecules may be changed, or broken down, but it takes a nuclear reaction of some kind to change the elements.

[Taverner]

2. So how does methane, a new element (not a chemical compound) come out of water and grass?

[HiFructosePronSyrup]

4. methane is CH4.

It's not a different element.

[ThomCat]

6. Methane is not an element.

Methane is CH4, or one carbon atom bonded to 4 hydrogen atoms.

There is both carbon and hydrogen in the food that is digested.

[HiFructosePronSyrup]

3. Those aren't new elements.

Methane is carbon and hydrogen. The cow also releases CO2. All the elements that go into a cow are the same elements that come out.

It's just chemical changes.

Are you asking how chemicals change?

[Taverner]

5. Ahhh OK - pardon my ignorance

I thought Methane was an element of its own. So the molecules get broken down and re-arranged into different chemical compounds.

[La Lioness Priyanka]

7. more or less.

[Orsino]

11. That's it exactly.

Chemical reactions will have either a positive or negative energy requirement, which is also included in the complete chemical equation. In this case, complex carbohydrates (grass) broken down by enzymes yield methane and other products, with a net production of energy--which is why the cows eat grass.

[EstimatedProphet]

8. Absolutely nothing, save low-level radiation

Grass is not an element. Neither is methane. Both of those are composed of compounds. Compounds are acted upon by chemical forces to be reduced to other compounds, or bonded together into other compounds.

[IndianaJones]

9. this is the wonder that science cannot explain. nt.

[Hand]

10. Insh'Allah. nt

[triguy46]

12. Hydrogen can become helium...

http://www.windows.ucar.edu/tour/link=/sun/Solar_interior/Nuclear_Reactions/Fusion/Fusion_in_stars/H_fusion.html

but you aren't going to cook this up in the back yard, no matter how good a meth chemist one might be.

[Lance_Boyle]

13. Cadmia, Philosopher's Wool, Powder of Algaroth... you know, the usual.

http://www.levity.com/alchemy/home.html

;-)