Question

"Li of group IA and Be of group IIA show diagonal relationship."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Answer 1

Li shows diagonal relationship with Mg and not Be.

A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table. These pairs lithium (Li) and magnesium (Mg), beryllium (Be) and aluminium (Al), boron (B) and silicon (Si) etc. exhibit similar properties.

Such relationship occurs because crossing and descending the periodic table have opposite effects. On moving across a period of the periodic table, the size of the atoms decreases, and on moving down a group the size of the atoms increases. Similarly, on moving across the period, the elements become progressively more covalent, less basic and more electronegative, whereas on moving down the group the elements become more ionic, more basic and less electronegative. Thus, on both descending a group and crossing the period by one element, the changes "cancel" each other out, and elements with similar properties which have similar chemistry are often found – the atomic size, electronegativity, properties of compounds (and so forth) of the diagonal members are similar.