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प्रश्न
Those elements impart colour to the flame on heating in it, the atoms of which require low energy for the ionisation (i.e., absorb energy in the visible region of spectrum). The elements of which of the following groups will impart colour to the flame?
(i) 2
(ii) 13
(iii) 1
(iv) 17
उत्तर
(i) 2
(iii) 1
Explanation:
The elements of group 1 (alkali metals) and group 2 (alkaline earth metals) have low ionization enthalpies. Therefore, they impart colour to flame.
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संबंधित प्रश्न
Among the second period elements the actual ionization enthalpies are in the
order Li < B < Be < C < O < N < F < Ne.
Explain why O has lower ΔiH than N and F?
How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?
What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?
The first ionization enthalpy values (in kJmol–1) of group 13 elements are:-
B | Al | Ga | In | Tl |
801 | 577 | 579 | 558 | 589 |
How would you explain this deviation from the general trend?
Explain the deviation in ionisation enthalpy of some elements from the general trend by using the given figure.
Explain the following:
Ionisation enthalpy decrease in a group from top to bottom?
Assertion (A): Generally, ionisation enthalpy increases from left to right in a period.
Reason (R): When successive electrons are added to the orbitals in the same principal quantum level, the shielding effect of inner core of electrons does not increase very much to compensate for the increased attraction of the electron to the nucleus.
Define ionisation enthalpy. Discuss the factors affecting ionisation enthalpy of the elements and its trends in the periodic table.
Discuss and compare the trend in ionisation enthalpy of the elements of group1 with those of group17 elements.
The decreasing order of the second ionization potential of K, Ca and Ba is ______.