Which of the following statements is true? the moon generates its own light.
the whole moon is lit by the sun at the same time.
there is no day or night on the moon.
only half the moon is lit by the sun at any one time.

Only half of the moon is lit by the sun at any time.

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

Answerstudying coal cumbustion as an energy source;