Question

elements of 1st period contains valence electron in which shell​

Answer 1

Answer:

The first electron shell, n = 1, consists of only one orbital, and the maximum number of valence electrons that a period 1 element can accommodate is two, both in the 1s orbital. The valence shell lacks "p" or any other kind of orbitals due to the general l < n constraint on the quantum numbers.

Answer 2

Elements of 1st period contain valence electrons in the K shell.

• The K shell is the lowest energy shell that can accommodate a maximum of two electrons. The other outer shells include L, M, and N which can accomodate 8, 18, and 32 electrons respectively.
• The K shell comprises one subshell called 1s where the electrons are oriented.
• The period 1 element is placed in the 1st row of the periodic table which includes hydrogen and helium.
• Elements of 1st period can be represented as:

1. Element- Hydrogen; Shell- K shell;                                                     Subshell- 1s; electon in subshell- 1 electron
2. Element- Helium; Shell- K shell;                                                         Subshell- 1s; electron in subshell- 2 electrons