Atomic Structure · JEE Main previous year questions

2018 4 questions

1. Q672018 · 15 Apr 2018 · Shift 1

   Ejection of the photoelectron from metal in the photoelectric experiment can be stopped by applying 0.5 V when the radiation of 250 nm is used. The work function of the metal is :

   1. A.4 eV
   2. B.4.5 eV
   3. C.5 eV
   4. D.5.5 eV
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   Answer: B

2. Q692018 · 15 Apr 2018 · Shift 1

   In the molecular orbital diagram for the molecular ion, ${\text{N}}_2^{+}$, the number of electrons in the ${\sigma }_{2{\text{p}}_z}$ molecular orbital is :

   1. A.0
   2. B.1
   3. C.2
   4. D.3
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   Answer: B

3. Q712018 · 15 Apr 2018 · Shift 1

   In graphite and diamond, the percentage of p-characters of the hybrid orbitals in hybridisation are respectively :

   1. A.33 and 25
   2. B.33 and 75
   3. C.50 and 75
   4. D.67 and 75
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   Answer: D

4. Q622018 · 8 Apr 2018 · Shift 1

   According to molecular orbital theory, which of the following will not be a viable molecule?

   1. A.${\text{He}}_2^{2+}$
   2. B.${\text{He}}_2^{+}$
   3. C.${\text{H}}_2^{-}$
   4. D.${\text{H}}_2^{2-}$
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   Answer: D