Energy Level Transitions | MCQs

Explanation

 The lifetime of an electron in a metastable state is significantly longer than in an ordinary excited state, typically by 10³ to 10⁵ times. 

Ordinary excited states have lifetimes on the order of 10⁻⁸ seconds. 

Metastable states have lifetimes that can range from microseconds to milliseconds and even longer, being orders of magnitude longer than typical excited states.

Therefore, options like 10³ or 10⁵ are appropriate estimations for how much longer a metastable state lifetime is compared to an ordinary excited state. 

Explanation

If an electron transitions from n=6 to n=7, the percentage increase in radius is approximately 33%.