Azimuthal quantum number defines :

• e/m ratio of electron

• angular momentum of electron

• spin of electron

• magnetic momentum of electron

The number of $\mathrm{\sigma }$ and $\mathrm{\pi }$ bonds present in pent-4-ene, I-yne is :

• 10 , 3

• 4 , 9

• 3 , 10

• 9 , 4

Assertion: During an adiabatic process, heat energy is not exchanged between the system and its surroundings.

Reason: The temperature of a gas increases when it undergoes an adiabatic expansion.

• If both assertion and reason are true and the 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.

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.

Assertion: An increase in surface area increases the rate of evaporation.
Reason: Stronger the intermolecular attractive forces, fast is the rate of evaporation at a given temperature.

• 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.

Assertion: Atoms can neither be created nor destroyed.
Reason: Under the similar condition of temperature and pressure, an equal volume of gases does not contain an equal number of atoms.

• 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.

Assertion: Mass and volume are extensive properties.
Reason: Mass/volume is also an extensive parameter.

• 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.

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.

19.

Assertion: Sigma ($\mathrm{\sigma }$) is a strong bond, while pi ($\mathrm{\pi }$) is a weak bond.
Reason: Atoms rotate freely about the pi ($\mathrm{\pi }$) bond.

• If both assertion and reason are true and the 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.

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.