The electronic configuration of four elements are given in brackets :L(1s2, 2s2) ;                     M(1s2, 2s22p5)Q(1s2, 2s22p6, 3s1) ;       R(1s2, 2s22p6)The element, that would most readily form ionic bond is :-

The element that would most readily form an ionic bond is the one that can easily lose or gain an electron to achieve a stable electron configuration.

Looking at the given electronic configurations:

L(1s2, 2s2) - This element is in the second period of the periodic table and has a full outer shell, so it is stable and unlikely to form an ionic bond.

M(1s2, 2s22p5) - This element is one electron short of a full outer shell. It can easily gain one electron to achieve a stable configuration, so it is likely to form an ionic bond.

Q(1s2, 2s22p6, 3s1) - This element has one electron in its outer shell. It can easily lose this electron to achieve a stable configuration, so it is also likely to form an ionic bond.

R(1s2, 2s22p6) - This element is in the second period of the periodic table and has a full outer shell, so it is stable and unlikely to form an ionic bond.

Therefore, the elements that would most readily form ionic bonds are M and Q.