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Atoms — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsAtoms1 Mark
Question
For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  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 is false and R is also false.
Assertion (A): Total energy of electron in an hydrogen atom is negative.
Reason (R): It is bounded to the nucleus.
✓

Answer

  1. Both A and R are true, and R is the correct explanation of A.
Explanation:

We know that $\text{E}=-\frac{13.6}{\text{n}^2}\text{eV}$

It shows that total energy of electron in a stationary orbit in a hydrogen atom is negative, which means the electron is bound to the nucleus and is not free to leave it.

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