Second Law of Thermodynamics

The second law of thermodynamics states the total entropy of a system will only increase and happens spontaneously which means that anything that happens on its own in nature will only increase in entropy. The energy only goes downhill. For example, ice melts on its own when placed at room temperature. The room temperature is higher than the freezing point and the ice melted. This also implied that the reaction does not reverse. You may ask then how does anything ever get frozen again? All the ice will just melt. In this case, energy has to provide in order to freeze water like what we do when we generate electricity to lower the temperature and freeze water.

Entropy to me is the energy within an object or substance. Water will have more heat than ice since it absorbed heat and melted hence it has more energy than ice.

The idea of second law of thermodynamics is important to biological and chemical process because it creates a balance for living organism and molecular substances on earth. In order for plants to take in water, plants have to first use energy to actively transport the minerals into its roots. However, after the active transport, water will flow in on its own, since there is a higher concentration in the roots. The second law of thermodynamics also explains why it is often hard to reverse a chemical reaction since it is always easier to go on the energy hill one way and harder the other way in reverse.