Q 8 Atomic structure 13.6xl.6xto-"
3.4 xl.6x 10-10
W'hich of the following curves may represent the speed of the electron in
atom as a function of the principal quantum number 'n'?
A sample of hydrogen atoms is irradiated with a light of photon energy 12.75 eV What is the minimum number
Of atoms the sample should contain in order to get six different photons in its emission ectrum?
6. Electrons in two identical atoms move around the nucleus in circular orbits Of R & AR. The ratio of the time
taken by them to complete one revolution is ;
7. The change in energy' when an electron is transferred between a neutral potassium and a neutral bromine atom
to produce a positively charged potassium cation and negatively charged bromine anion, K(g) + Br(g) —s Ve(g)
+ Br(g), is 93.6 kJ mol-l. The ionization energy of a potassium atom is 4.34 eV. Calculate the electron affinity
of a neutral bromine atom.
(B) -3.37 ev
(D) 3.37 Ev
8. A proton and an - particle are accelerated through the same potential difference. The ratio of their de
Broglie wavelength is :
9. Light of wavelength shines on a metal surface with intensity X, and the metal emits•Y electrons persecond,
of average energy Z. Select the correct statement.
(A) if is halved, Z is unchanged
Jej if X is increased, Y is not changed
(B) if R is halved, Z will increase
(D) if X is increased, Y will decrease