Which of the following is an essential condition for a redox reaction?

a. the reactants should be two elements.
b. the reactants should be two compounds.
c. the oxidation state of all the atoms should change.
d. the oxidation state of at least two atoms should change.

Answer explain why it is not possible to deduce a complete order of reactivity.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.