Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.7

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11th CBSE

IMPORTANT

Earn 100

Calculate the wavelength, frequency and wave number of a light wave whose time period is $2 .0 \times 10^{- 10} s$ .

Important Questions on Structure of Atom

HARD

11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.8

What is the number of photons of light with a wavelength of

4000 pm

that provide

1 J

of energy?

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11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.9

A photon of wavelength

4 \times 10^{- 7} m

strikes on metal surface, the work function of the metal being

2 .13 eV

. Calculate
(i) the energy of the photon

(eV)

,
(ii) the kinetic energy of the emission and
(iii) the velocity of the photoelectron

(1 eV = 1 .6020 \times 10^{- 19} J)

.

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11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.1

Electromagnetic radiation of wavelength

242 nm

is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in

kJ {mol}^{- 1}

.

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11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.11

A

25

watt bulb emits monochromatic yellow light of a wavelength of

0 .57 µ m

. Calculate the rate of emission of quanta every second.

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IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.12

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength

6800 \overset{°}{A}

. Calculate threshold frequency

(ν_{0})

and work function

(W_{0})

of the metal.

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11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.13

What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with

n = 4

to an energy level with

n = 2

?

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IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.14

How much amount of energy is required to ionise a

H

atom if the electron occupies

n = 5

orbit? Compare your answer with the ionization enthalpy of

H

atom (energy required to remove the electron from

n = 1

orbit).

MEDIUM

11th CBSE

IMPORTANT

Textbook for Class XI Chemistry Part I>Chapter 2 - Structure of Atom>EXERCISES>Q 2.15

What is the maximum number of emission lines when the excited electron of a

H

atom in

n = 6

drops to the ground state?