11Na24 1s radioactive and it decays to: from Chemistry Stru

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 Multiple Choice QuestionsMultiple Choice Questions

411.

The emission spectrum of hydrogen discovered first and the region of the electromagnetic spectrum in which it belongs, respectively are

  • Lyman, ultraviolet

  • Lyman, visible

  • Balmer, ultraviolet

  • Balmer, visible


412.

As per de-Broglie's formula a macroscopic particle of mass 100 g and moving at a velocity of 100 cm s-1 will have a wavelength of

  • 6.6 × 10-29 cm

  • 6.6 × 10-30 cm

  • 6.6 × 10-31 cm

  • 6.6 × 10-32 cm


413.

Assertion: For Balmer series of hydrogen spectrum, the value n1 = 2 and n2 = 3, 4, 5.
Reason: The value of n for a Line in Balmer series of hydrogen spectrum having the highest wavelength is 4 and 6.

  • If both assertion and reason are true and reason is a correct explanation of the assertion.

  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

  • If the assertion is true but the reason is false.

  • If both the assertion and reason are false.


414.

Assertion: Absolute values of the internal energy of substances can not be determined.
Reason: It is impossible to determine the exact values of constituent energies of the substances.

  • If both assertion and reason are true and reason is a correct explanation of the assertion.

  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

  • If the assertion is true but the reason is false.

  • If both the assertion and reason are false.


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415.

Assertion: The absorption spectrum consists of some bright lines separated by dark spaces.
Reason: Emission spectrum consists of dark lines.

  • If both assertion and reason are true and reason is a correct explanation of the assertion.

  • If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

  • If the assertion is true but the reason is false.

  • If both the assertion and reason are false.


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416.

11Na24 1s radioactive and it decays to:

  • 9F20 and α-particles

  • 13Al24 and positron

  • 11Na23 and neutron

  • 12Mg24 and β-particles


D.

12Mg24 and β-particles

11Na24  12Mg24 (stable) + -1β0


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417.

Which of the following does not represent the mathematical expression for the Heisenberg uncertainty principle?

  • . h/(4π)

  • . ∆v  h/(4πm)

  • ∆E . ∆t  h/(4π)

  • ∆E . ∆x  h/(4π)


418.

During the emission of a positron from a nucleus, the mass number of the daughter element remains the same but the atomic number

  • is decreased by 1 unit

  • is decreased by 2 units·

  • is increased by 1 unit

  • remains unchanged


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419.

β- emission is always accompained by

  • formation of antineutrino and α-particle

  • emission of α-particle and γ-ray

  • formation of antineutrino and γ-ray

  • formation of antineutrino and positron


420.

The value of Planck's constant is 6.63 x 10-34 Js. The speed of light is 3 x 1017 nms-1. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of 6 x 1015 s-1?

  • 10

  • 25

  • 50

  • 75


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