Quintal definition: a unit of weight equal to 100 pounds | Meaning, pronunciation, translations and examples English Dictionary | Thesaurus | Translator | Grammar | Scrabble | Blog English
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy. If it is in the second energy level, it must have -3.4 eV of energy. An electron in a hydrogen atom cannot have -9 eV, -8 eV or any other value in between. Let's say the electron wants to jump from the first energy level, n = 1, to the second energy level n = 2. The second energy level has higher energy than the first, so to move from n = 1 to n = 2, the electron needs to gain energy.
The First Law of Thermodynamics states that during any reaction the total energy in the universe remains constant. The Second Law of Thermodynamics states that during any reaction the total useful energy in the universe (the energy that is useful for doing work) will decrease. For example, consider a ball rolling downhill, moving faster and faster.