Question

What is an orbital? How is it different from Bohr's orbit?

Answer 1

Orbital, in chemistry and physics, a mathematical expression, called a wave function, that describes properties characteristic of no more than two electrons in the vicinity of an atomic nucleus or of a system of nuclei as in a molecule.

Bohrs orbit looks like a loop of thread of zero diameter. The electron on Bohrs orbit are moving around the nucleus like planets around the sun on a deterministic route. Schrodinger orbials are diffuse splotches like frogs male gametes floating in water. His orbitals discribe the probability of electron being on an P(x,y,z) spacial point within unit time. In case of the spherically symmetric s-orbitals this probability within the volume of the nucleus is not zero.

The chemical bond distort p, d and f orbitals which change the probabilistic density of s-electrons within the nucleus, and cause a measurable shift of energy levels of the nucleus. That is the base of the Mossbauer spectrosopy.