Correct Answer: Option C
Reason:
<span>The </span>Pauli Exclusion Principle<span> states as '<em>in an atom or molecule, no two electrons can have the same four electronic quantum numbers. Further, an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.</em>'
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Thus, it can be seen that in option C, electrons in last 2 subshell have electrons with same spin, which is a violation of Pauli Exclusion Principle .
Answer:
As air rises upwards it expands and cool down and then it stops rising when it matches the temperature of surrounding air. ... Cool air can't hold moisture as much as warm air. So moisture condenses into droplets of water and thus forming cloud.
The valence electrons determine how reactive an element is, and since Sodium and other alkali metals could easily lose an electron, they become very reactive to be stable.