Question

which principal is not followed in writing the electronic configuration of
$1s { \:}^{2} 2s {}^{1 \:} 2p {}^{4}$
give reasons?​

Answer 1

Answer:

Aufbau Principle is violated as the orbital having lower energy must be filled first. So 1s could not be vacant in 1s

0

2s

2

2p

4

.

An electron having the lowest value of (n+l) will be filled first.

Explanation:

both of these types of notations, the order of the energy levels must be written by increased energy, showing the number of electrons in each subshell as an exponent. In the short notation, you place brackets around the preceding noble gas element followed by the valence shell electron configuration. The periodic table shows that kyrpton (Kr) is the previous noble gas listed before iodine. The noble gas configuration encompases the energy states lower than the valence shell electrons. Therefore, in this case [Kr]=1s22s22p63s23p64s23d104p6