Coal
Coal is a sedimentary rock that is made from mostly plant debris. This debris is usually formed in a swampy environment and is usually mined and used for fuel! Hope this helps!
The 3d sublevel is not filled until after the 4s sublevel, because the 3d sublevel has more energy than the 4s sublevel, and less energy than the 4p sublevel. (:
Answer:
In a chemical reaction, chemical equilibrium is the state in which the forward reaction rate and the reverse reaction rate are equal. The result of this equilibrium is that the concentrations of the reactants and the products do not change.
Explanation: