Which of the following is a renewable energy source

trees

coal

oil

natural gas

oil

Explanation:

oil is made by our mistakes and we make a lot of them so it is renewable

A) Trees

Option A is the Answer

Explanation:

Renewable energy sources are energy sources that are always being replenished. They can never be depleted. Some examples of renewable energy sources are solar energy, wind energy, hydropower, geothermal energy, and biomass energy.

Renewable energy sources—solar, hydro, wind, and so forth—are attractive because they are non polluting and do not require imported fuel.  

Here, among the options, trees are easily renewable compared to all other sources mentioned there. We cannot renew coal, oil or natural gas easily as it takes so many long years to accomplish it.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

he would use the colour black