Energy level,orbit,orbital&quantum number.what exactly is the difference?

Answer 1

They are all related, and interconnected. But, there is some distinction to help a person get exactly what they want.

The energy level is the energy an electron possesses regardless of what orbital it's in.

There are several perspectives in looking at this, but start w/ this fairly simple one. If an electron is in the lowest state available to it, it's the "ground state", or "zero energy". This state has a distinct quantum number and orbital associated with it.
Energy has to be added TO the electron to put it into a higher energy state. That higher energy state would be described by different quantum number and/or orbital.

The quantum number is a rough guide as to how "far" the orbitals are from the nucleus. As a rule of thumb, the bigger the quantum number, the higher the energy state. Also, the larger the quantum number, the more orbitals that exist at that "distance".

The orbital is a specific region around the nuclues that an electron can occupy. It's drawn as shapes (s-orbital: sphere, p-orbital: dumbell, d-orbital: 4 lobes, etc) but that's usually a shape where you're probability of finding the electron is high (say 90% or better).

Each quantum number has it's own set of orbitals. Their shapes are similar, but higher quantum numbers usually mean "bigger" orbitals. Each s-orbital is a sphere, but a 2 s-obital is bigger than a 1 s-orbital.

And remember, higher quantum numbers mean more types of orbitals. There is only a 1s orbital, there is no 1p orbiatl. There are 2s AND 2p orbitals, but no 2d orbitals. Etc.

Orbits are a crude description of how an electron moves around the nucleus: like planets about the sun. You see them in the classic drawing of an atom, w/ the 3 electrons and their loops, but it's not a valid scientific description.

Answer 2

Energy level (n) is the Principle quantum number, which you learn about in chemistry. The different energy levels are also called shells. There are also 3 other quantum numbers. Another one is (l). This quantum number ranges from 0 to (n-1). These numbers can be considered subshells. These subshells are called s, p, d, f. Within each subshell, there are (2l + 1) orbitals. An orbital is an area in the atom where an electron is likely to be. Each orbital can house two electrons, each spinning in a different direction. Also, electrons occupy the lowest level orbitals first.

Answer 3

Its been a little while since I took quantum but I think they are the same.