atom

Question 1

Define the term “Intensity”

Answer 1

The intensity of radiation can be defined as the energy associated with photons emitted from a unit surface area in unit time.

Question 2

impact parameter

Answer 2

The impact parameter is the perpendicular distance of the
initial velocity vector of the a-particle from the centre of the nucleus

Question 3

closest approach

Question 4

bohr postulates

Answer 4

an atom could revolve
in certain stable orbits without the emission of radiant energy

the electron revolves around the nucleus only in those
orbits for which the angular momentum is some integral multiple of
h/2p

an electron might make a transition from one of its
specified non-radiating orbits to another of lower energy. When it
does so, a photon is emitted having energy equal to the energy
difference between the initial and final states. The frequency of the
emitted photon is then given by
hn = Ei
– Ef

Question 5

L?

Answer 5

mvr=nh/2pie

Question 6

drawbacks of bohr

Answer 6

The Bohr model is applicable to hydrogenic atoms. It cannot be
extended even to mere two electron atoms such as helium

the model is unable to explain the
relative intensities of the frequencies in the spectrum

Question 7

series order

Answer 7

l,ba,p,br,pf

Question 8

Rutherford
model postulates
?

Answer 8

(A) Most of the space inside an atom is empty.
(B) The electrons revolve around the nucleus under the influence of coulomb
force acting on them.
(C) Most part of the mass of the atom and its positive charge are concentrated
at its centre.

Question 9

Write the limitations of Bohr Atom Model

Answer 9

(i) The Bohr model is applicable to hydrogenic atoms. It cannot be
extended two or more electron atoms.
(ii) The Bohr model is unable to explain the intensity variations of the
frequencies in hydrogen spectrum