Planck's constant =
6.62607004 × 10-34 m2 kg / s
Explanation:
Step by Step explanation
The Planck constant, or Planck's constant, is a fundamental physical constant denoted h, and is of fundamental importance in quantum mechanics. A photon's energy is equal to its frequency multiplied by the Planck constant. Due to mass–energy equivalence, the Planck constant also relates mass to frequency. Wikipedia
It is a single replacement reaction. Li and Mg switch places.
The answer is 5 gold token from Chuck E. Cheese
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: