# Orbital path of atoms

• B
An nucleus of an atom is really surrounded by circular orbits or not. And why there is a pattern that orbit k can contain only two electrons, orbit l can contain only 8 electrons and so on. But at some places I observe that the nucleus of an atom is surrounded by cloud like structure containing electrons. So what is true, according to Bohr's model of atom electron moves around nucleus in a specific place which is later considered orbit.

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blue_leaf77
Homework Helper
An nucleus of an atom is really surrounded by circular orbits or not.
The answer is no, not in the same sense as planets revolves around the sun. There is one fundamental principle in QM which prevents you from tracking the position of those electrons in any given time.
So what is true, according to Bohr's model of atom electron moves around nucleus in a specific place which is later considered orbit.
Bohr's model of atom has long been put aside and replaced by modern QM.
And why there is a pattern that orbit k can contain only two electrons, orbit l can contain only 8 electrons and so on.
What is meant by "orbit" around the nucleus does not exactly have the same physical meaning as the planetary orbits. Orbit in QM mechanics refers to the so-called subshell of the corresponding atom. Following the theory of each electron being subjected under an effective potential, it turns out that you can describe the orbit/subshell of each electron similar to those as in hydrogen-like atom. The maximum number of electrons allowed to occupy a given orbit/subshell is required by Pauli exclusion principle.

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shina
The answer is no, no in the same sense as planets revolves around the sun. There is one fundamental principle in QM which prevents you from tracking the position of those electrons in any given time.

Bohr's model of atom has long been put aside and replaced by modern QM.

What is meant by "orbit" around the nucleus does not exactly have the same physical meaning as the planetary orbits. Orbit in QM mechanics refers to the so-called subshell of the corresponding atom. Following the theory of each electron being subjected under an effective potential, it turns out that you can describe the orbit/subshell of each electron similar to those as in hydrogen-like atom. The maximum number of electrons allowed to occupy a given orbit/subshell is required by Pauli exclusion principle.
Yaa I am truely satisfied with you but I don't know the reason that why limited number of electrons are there in discrete shell around nucleus of an atom

mfb
Mentor
Pauli principle: No two electrons can be in the same state. The innermost shell just has two states (spin up and spin down for the same wave function in space), the next shell has 8 (4 pairs of spin up and down each), and so on. A very reasonable sounding, but not really accurate model: larger shells have "more space" for more different states. A better explanation would need some more understanding of quantum mechanics.

shina
Pauli principle: No two electrons can be in the same state. The innermost shell just has two states (spin up and spin down for the same wave function in space), the next shell has 8 (4 pairs of spin up and down each), and so on. A very reasonable sounding, but not really accurate model: larger shells have "more space" for more different states. A better explanation would need some more understanding of quantum mechanics.