Following Aufbau rule and Hund principle, the order of filling of the orbitals is this:

So, the first, second, and fourth option are not correct.
The third option does meet the filling order.
Answer:
Answer:
812.754 miles
Why:
0.621371 miles per km
Answer:
Two reagents that can be used to distinguish between ethane and ethyne are Tollens' reagent and ammoniacal CuCl solution.
Conduct creates, convect rubs, and radiation gives heat.