CBSE 2023 · Region 2 · Set 1 · Q23 · 2 marks
What is meant by ionisation energy ? Write its value for hydrogen atom.Define the term, mass defect. How is it related to stability of the nucleus?
What is meant by ionisation energy ? Write its value for hydrogen atom.
Define the term, mass defect. How is it related to stability of the nucleus?
Marking-scheme solution
(a)
Ionization energy is the minimum energy required to remove an electron from an isolated atom of an element.
Alternatively
It is the energy required to excite an electron from energy level $\displaystyle n = 1$ to $\displaystyle n = \infty$ from an isolated atom of an element.
The ionization energy for hydrogen atom is $\displaystyle 13.6$ eV.
OR(b) Mass defect is the difference between the actual mass of the nucleus and the sum of the masses of its nucleons.
Greater the mass defect, greater will be the binding energy and the nucleus will be more stable.
AtomsBohr Model of the Hydrogen AtomRemembervery_short_answereasy
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CBSE Class 12 Physics past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.