The energy associated with the first orbit in the hydrogen atom is – 2 . 18 × 10 - 18 J atom - 1 . What is the energy associated with the fifth orbit ?

E n = - 13 .6 Z 2 n 2 eV Given: hydrogen orbit ( n ) = 5 For hydrogen, atomic number ( Z ) = 1 E 5 = - 13 .6 5 2 eV = - 13 .6 25 eV = - 0 . 544 eV ( ∴ 1 eV = 1 .6 × 10 - 19 J ) = - 0 . 544 eV × 1 .6 × 10 - 19 J = - 8 .704 × 10 - 20 J

The energy associated with the first orbit in the hydrogen atom is – 2 . 18 × 10 - 18 J atom - 1 . What is the energy associated with the fifth orbit ?

E n = - 13 .6 Z 2 n 2 eV Given: hydrogen orbit ( n ) = 5 For hydrogen, atomic number ( Z ) = 1 E 5 = - 13 .6 5 2 eV = - 13 .6 25 eV = - 0 . 544 eV ( ∴ 1 eV = 1 .6 × 10 - 19 J ) = - 0 . 544 eV × 1 .6 × 10 - 19 J = - 8 .704 × 10 - 20 J

The mass of an electron is 9 .1 × 10 - 31 kg . If its K.E. is 3 .0 × 10 - 25 J , calculate its wavelength.

Given: The mass of an electron = 9 .1 × 10 - 31 kg Kinetic energy (K.E) of the electron = 3 .0 × 10 - 25 J Since K.E. = 1 2 mv 2 ∴ Velocity v = 2 K . E m = 2 × 3 .0 × 10 - 25 J 9 . 1 × 10 - 31 kg = 0 . 6593 × 10 6 v = 811 . 99 ms - 1 From de Broglie’s equation, wavelength ( λ ) = h mv h = 6 .62 × 10 - 34 Js Substituting all values in the expression of λ : λ = 6 .62 × 10 - 34 Js 9 .1 × 10 - 31 kg 811 . 99 m s - 1 = 8 .959 × 10 - 7 m ≅ 8 .95 × 10 - 7 m

E M B I B E

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.16

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The energy associated with the first orbit in the hydrogen atom is $- 2.18 \times 10^{- 18} J {atom}^{- 1}$ . What is the energy associated with the fifth orbit ?

Important Questions on Structure of Atom

MEDIUM

11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.16

Calculate the radius of Bohr’s fifth orbit for hydrogen atom.

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11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.17

Calculate the wavenumber for the longest wavelength transition in the Balmer series of atomic hydrogen.

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11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.18

What is the energy in joules, required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is