Q 8 Atomic structure 13.6xl.6xto-"
6.62xto• x3x10S
3.4 xl.6x 10-10
3.4x1.6x10-19
4.
5.
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?
4
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 ;
Jan
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
(C) -5.31eV
(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
CHEMISTRY
(B) if R is halved, Z will increase
(D) if X is increased, Y will decrease
