Sakshi
Last Activity: 9 Years ago
hey student..
Write the electronic configuration. The highest Principal quantum number in the configuration gives the period, and the Electron shell(subshell) coming last is the group of the element. The number of electrons filled in the last subshell gives the position of the element within the group.
For example,
The configuration of iron is
4 is the highest principal quantum number.Hence, it belongs to the 4th period.
Last subshell is the d- subshell. Hence it belongs to d-group.
6 electrons are filled in last subshell.Hence it the 6th element in the d-group of the 4th period.