What was niels bohr’s theory was based on?

Niels Bohr was a Danish physicist who contributed to the understanding of the atom and quantum mechanics. He was awarded the Nobel Prize in Physics in 1922.

Based on the theories of Ernest Rutherford, he published his own atomic model (Bohr's atomic model) in 1913, introducing the theory of quantized orbits, which in quantum mechanical theory consists of the characteristics that, around the Atomic nucleus, the number of electrons in each orbit increases from the inside to the outside.

In his model, in addition, the electrons could fall (to go from one orbit to another) from an outer orbital to an inner one, emitting a photon of discrete energy, fact on which quantum mechanics is based.

In 1922 he received the Nobel Prize in Physics for his work on atomic structure and radiation.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west