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.
This space is called the first energy shell. If there are three electrons in an atom, the first two will be found in the first energy shell. The third electron will have to settle for the second energy shell, a three-dimensional space a little farther from the nucleus, where it will be alone.