Why is the concept of X-rays explained using Bohr model knowing that it is incorrect We were explained characteristic X rays using the Bohr model and were told that they are formed when an electron is knocked out of its shell and another electron from higher shell comes down emitting X rays. However it seems wrong to use the Bohr model as Schrödinger's model had proved it wrong.
 A: The description you've provided,

an electron is knocked out of its shell and another electron from higher shell comes down emitting X rays

is as applicable to the Bohr model as it is to full-blown quantum mechanics. As such, your core question is based on a faulty assumption,

the concept of X-rays [is] explained using Bohr model.

The Bohr model is indeed wrong, and it should not be used in situations where its predictions differ from those of full-blown QM. Since this isn't such an instance, it's fine to work mentally within that framework, as the actual calculations are done using equivalent processes within the QM formalism.
A: We don't use the Bohr model to describe X-ray emission. The Bohr model can only be used for single electron atoms as it doesn't include the repulsion between electrons that we get when two or more electrons are present.
When we talk about X-ray emission being due to electrons moving between shells the shells referred to are the atomic orbitals. These are calculated using the Schrodinger equation with some suitable approximation such as a mean field approach. Both the Bohr model and Schrodinger's equation predict discrete energy levels, but they are completely different. They have equal energies only for single electron atoms.
