Assertion (A): | First ionization energy for nitrogen is lower than that of oxygen. |
Reason (R): | Across a period, effective nuclear charge decreases. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Beryllium has more first ionization potential than Boron. |
Reason (R): | Boron has a lower electron affinity than beryllium. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The shielding effect increase as we go down the group. |
Reason (R): | More is the number of electrons in the penultimate shell, and more is shielding. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Ionisation potential across the period is Na < Al < Mg < Si. |
Reason (R): | Ionisation potential decreases with decrease in atomic size. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | Electron gain enthalpy of oxygen is more than that of sulphur. |
Reason (R): | Oxygen is more electronegative than sulphur. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The first ionization energy of aluminum is lower than that of magnesium. |
Reason (R): | The ionic radius of aluminium is smaller than that of magnesium. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) and (R) both are False. |
Assertion (A): | The 19th electron in the potassium atom enters into the 4s-orbital, not into the 3d orbital. |
Reason (R): | (n + l ) rule is followed for determining the orbitals of the lowest energy state. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | Na+ and Al3+ are isoelectronic but the magnitude of ionic radius of Al3+ is less than that of Na+. |
Reason (R): | The magnitude of effective nuclear charge of the outer shell electrons in Al3+ is greater than that in Na+. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True and (R) is False. |
4. | Both (A) and (R) are False. |