What is the correct electron configuration for magnesium? ( use periodic table)
a) 1s22s22p5
b) 1s22s22p6
c) 1s22s22p63s2
d) 1s22s22p63s23p2

The answer is c)

Explanation:

The neutral atoms have the same number of protons (positive charge) and electrons (negative charge). So in the periodic table the atomic number shows the number of protons and electrons.

Magnesium has an atomic number of 12, so it has 12 electrons. Electronic configuration shows the location of the electrons around the atom nucleus. To know its electronic configuration we will need to use  the order of fill (the chart in the image), which indicates how the electrons are placed into the orbitals based on the order of their energy. The lowest energy orbitals (such as ) will be occupied first.

So according to this Magnesium electronic configuration will be as 2+2+6+2=12 electrons. The superscript of each orbital is the amount of electrons that occupied it.

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .