Question

Question #ed5f9

Answer 1

Oxirreduction, or combustion.

Explanation:

Reactions of the type

`4M + O_2 rarr 2M_2O`
`2M + O_2 rarr 2MO`
`4M + 3O_2 rarr 2M_2O_3`

Where `M` is a metal are oxirreduction (or redox) reactions since the metals goes from having a `0` net charge to a positive one (it's being oxidized) whereas Oxygen goes from having a `0` net charge to `-2`, being reduced.

Which of the equations will happen, will depend on the metal. But reactions of this type can happen with other compounds, including, for example the combustion of coal

`C + O_2 rarr CO_2`

The combustion of hydrocarbons in general

`2C_xH_y + (4x+y)O_2 rarr 2xCO_2 + yH_2O`

(Whereas any present oxygen may or may not become oxygen gas, and nitrogen or sulfur will go to an oxide depending on the amount of oxygen available among other things).