GENERAL KNOWLEDGE

Detailed explanation-1: -Each orbital holds two electrons which differ in a property known as spin. Orbital: A region of space within an atom where an electron in a given subshell can be found. Any orbital can hold a maximum of 2 electrons with opposite spin. The first shell has one 1s orbital and holds 2 electrons.

Detailed explanation-2: -Each subshell contains a distinct number of orbitals according to the Principal Quantum number( ). Each orbital can occupies two electrons in opposite spins according to the Pauli Exclusion Principle.

Detailed explanation-3: -Pauli’s Exclusion Principle states that no two electrons in the same atom can have identical values for all four of their quantum numbers. In other words, (1) no more than two electrons can occupy the same orbital and (2) two electrons in the same orbital must have opposite spins (Figure 46(i) and (ii)).

Detailed explanation-4: -Electrons are magnets, they have magnetic fields. Those fields have only two possible orientations, and a single orbital can only be occupied by two electrons if those orientations are mutually opposed.

Detailed explanation-5: -Thus, the orbital angular momentum of an electron in 2s orbital is 0.