1) Energy of an electron is given by E=−2.178×10−18J(Z2n2) Wavelength of light requires to excite an electron in an hydrogen atom from level n=1 to n=2 will be (h= 6.62 x 10-34 J s and c=3.0 x 108 ms-1) A) 1.214×10−7m B) 2.816×10−7m C) 6.500×10−7m D) 8.500×10−7m Answer: Option AExplanation:△E=2.178×10−18(112−122)=hcλ 2.178×10−18(112−122) =6.62×10−34×3.0×108λ=1.21×10−7m