Answer to Question #276699 in General Chemistry for Hutchii

Question

Choose three among the five principles/rules in Atom's Electronic Structure. How would you discuss those you have chosen to a sixth grader in a manner that he/she can understand?

Answer 1

Energy of Electrons in Atomic Orbitals

The central structure of an atom is the nucleus, which contains protons and neutrons. This nucleus is surrounded by electrons. Although these electrons all have the same charge and the same mass, each electron in an atom has a different amount of energy. Electrons with the lowest energy are found closest to the nucleus, where the attractive force of the positively charged nucleus is the greatest. Electrons that have higher energy are found further away.

Energy Quantization

When the energy of an atom is increased (for example, when a substance is heated), the energy of the electrons inside the atom is also increased—that is to say, the electrons get excited. For the excited electron to go back to its original energy, or ground state, it needs to release energy. One way an electron can release energy is by emitting light. Each element emits light at a specific frequency (or color) upon heating that corresponds to the energy of the electronic excitation.

It is helpful to think of this like going up a flight of steps. If you don’t lift your foot enough, you will bump into the step and be stuck on the ground level. You need to lift your foot to the height of the step to move on. The same goes for electrons and the amount of energy they can have. This separating of electrons into energy units is called quantization of energy because there are only certain quantities of energy that an electron can have in an atom. The energy of the light released when an electron drops down from a higher energy level to a lower energy level is the same as the difference in energy between the two levels.

Electron Shells

Here, electrons are arranged in energy levels, or shells, around the nucleus of an atom. Electrons that are in the first energy level (energy level 1) are closest to the nucleus and will have the lowest energy. Electrons further away from the nucleus will have higher energy. An atom’s electron shell can accommodate 2n² electrons, where n is the energy level. For example, the first shell can accommodate 2 x (1)² or 2 electrons. The second shell can accommodate 2 x (2)², or 8, electrons.