Short question atomic structure

QUESTION:What is origin of hydrogen spectrum on the basis of Bohr’s model?Ans.When hydrogen gas is heated or subjected to electric discharge, its electrons jump from lower orbit to higher orbit by absorbing suitable wavelengths. When they come back to lower orbit they emit the same amount of energy which appeared as bright lines on screen. The Lyman series is obtained when electron jumps from n2 = 2, 3,4.5 so on to n1 = 1. Balmer , Paschan,Bracket and Pfund serieses are obtained when electron jumps from higher to lower n1 = 2, 3,4,5 respectively.QUESTION: What are X-rays? What is their origin? Ans. X-rays are produced when rapidly moving electrons collide with heavy metal anode in the discharge tube.Origin of x-rays: When cathode rays collide with target metal anode in the discharge tube, they knock out inner shell electrons of metal atom. Due to removal of inner shell electrons, vacancies are created in inner shells. When electrons in higher energy levels fall into lower energy levels, they emit radiations which are called x-rays. When electrons fall into K shell they give rise to K series and they fall into L shell they bring about L series etc. QUESTION: The x-rays produced in a discharge tube experiment are characteristics of target metal. Justify it. or How was the idea of atomic number derived from the discovery of X-rays?Ans.Relationship between frequency of a particular line of X-rays and atomic number Z of the element emitting it is given by Mosley law. √v = a(Z - b) where v is frequency of particular line ‘a’ and ‘b’ are the constants.If we plot graph between √v for K-series of x-rays and Z then straight line is obtained. This indicates that square root of frequency is directly proportional to atomic number not atomic mass of element and only atomic number determines element’s characteristics physical and chemical properties. So x-rays are characteristics of target metal.QUESTION: What is Moseley’s law?Ans.Statement: This law states that the frequency of a spectral line in x-rays spectrum varies as the square of atomic number of an element emitting it. Mathematically, √v = a(Z - b) This is mathematical form of Moseley’s law. Where v is frequency of a particular spectral line, Z is atomic number of target metal used as anode, a is proportionality constant and b is screening constant of metal.QUESTION:How does Bohr’s model justify Moseley’s equation?Ans.According to Moseley law the relationship between x-ray spectral line and atomic number is given as √v = a(Z - b) or √v ∝ Z ccording to Bohr’s atomic model frequency of spectral line depends on the charge of nucleus. i.e ∆E =hν= -(Z^2 me^4)/(8π〖ϵ_o〗^2 h^2 ) [1/(n_1^2 ) - 1/(n_2^2 )] or ν = (Z^2 me^4)/(8π〖ϵ_o〗^2 h^3 ) [1/(n_1^2 ) - 1/(n_2^2 )] or ν ∝ Z^2 or √v ∝ Z This indicates that Bohr’s model justify the Moseley equation.