We get the word 'allegory' from the Latin word 'allegoria ,' taken from the Greek word for 'veiled language.' Think of an allegory as an umbrella term for stories with deeper meaning-stories that are more than stories. Some allegories are very heavily veiled and might require an English professor to explain them to you.
A neutral phosphorus atom has 15 electrons. Two electrons can go into the 1 s subshell, 2 can go into the 2 s subshell, and 6 can go into the 2 p subshell. That leaves 5 electrons. Of those 5 electrons, 2 can go into the 3 s subshell, and the remaining 3 electrons can go into the 3 p subshell.
Once one shell is full, the next electron that is added has to move to the next shell. So... for the element of PHOSPHORUS, you already know that the atomic number tells you the number of electrons. That means there are 15 electrons in a Phosphorus atom. Looking at the picture, you can see there are two electrons in shell one, eight in shell two, and five in shell three.