What is the electron configuration of phosphorus

1s², 2s², 2p⁶, 3s², 3p⁵

Given

Phosphorus element

Required

The electron configuration

Solution

The energy level is expressed in the form of electron configurations.  

Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f.

Charging electrons in the sub shell uses the following sequence:  

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.  

Electron configurations are based on the number of electrons in the atomic number.

The atomic number of the phosphorus is 15, so the number of electrons is 15.

The configuration:

1s², 2s², 2p⁶, 3s², 3p⁵

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current