The answeris c, chemicalchange because the atoms in woodand oxygen are rearranged.
Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced equation will be:

5CO2 should be in the blank spot.
the reaction would be 7
Answer:
high pressure of 200-300 atm.
low temp. of between 400-500 degrees celsius:this is for continuous development of ammonia since it decomposes at high temp fathermore the reaction is exothermic
a catalyst to speed up the rate of reaction:i guess it is finely divided iron impregnated in aluminium oxide
platinum can be used as a catalyst but it is easily poisoned
hope it helps
Explanation: