State one human activity that increase the amount of carbon dioxide in the atmosphere today.

Burning of fossil fuels

Explanation:

Human activities that increase the amount of carbon dioxide in the atmosphere are;

1) Burning of fossil fuels in industrial and  internal combustion engines

2) Depletion of the available forest cover, due to the consumption of wood as a raw material

3) Farming expansion  that lead to clearing of forests for farming

4) Industrial activities such as the production of cement

5) Deforestation to provide land for development including buildings and infrastructure.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.