ATOMIC STRUCTURE JEE

If the kinetic energy of an electron is increased four times, the wavelength of the de-Broglie wave associated with it would become:

• Two times

• Half

• One fourth

• Four times

Calculate the wavelength in nanometer associated with a proton moving at 1.0x10³ m/s (mass of proton = 1.67x10^-27 kg and h= 6.63x10^-34 Js)

• 2.5 nm

• 14.0 nm

• 0.032 nm

• 0.40 nm

The radius of the second Bohr orbit for the hydrogen atom is:

• 1.65 A

• 4.76 A

• 0 529 A

• 2.12 A

The energy required to break one mole of Cl-Cl bonds in Cl₂ is 242 kJ/mol. The longest wavelength of light capable of breaking a single Cl-Cl bond is (c= 3x10⁸ m/s and N_A = 6.02x10²³ mol):

• 494 nm

• 594 nm

• 640 nm

• 700 nm

Ionisation energy of He⁺ is 19.6x10^-18 J/atom. The energy of the first stationary state (n=1) of Li²⁺ is:

• 8.82x10^-17 J/atom

• 4.41x10^-16 J/atom

• -4.41x10^-17 J/atom

• -2.2x10^-15 J/atom

The frequency of light emitted for the transition n=4 to n=2 of He⁺ is equal to the transition in H atom corresponding to which of the following:

• n=3 to n=1

• n=2 to n=1

• n=3 to n=2

• n=4 to n=3

• 2.650x10^-7 m

• 1.325x10^-7 m

• 1.325x10^-10 m

• 5.300x10^-10 m

The de-Broglie wavelength of a car of mass 1000kg and velocity 36km/hr is:

• 6.626x10^-31 Js

• 6.626x10^-34 Js

• 6.626x10^-38 Js

• 6.626x10^-30 Js

If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of Li²⁺ is:

• 13.6 eV

• 30.6 eV

• 122.4 eV

• 3.4 eV

According to Bohr's theory, the angular momentum of an electron in 5^th order orbit is:

• 25h/pi

• 1.0h/pi

• 10h/pi

• 2.5h/pi