Question

Give some of the diagonal relationship between beryllium and aluminium-

Answer 1

We need to know that the diagonal relationship mainly exists in the elements present in the second and third periods of the periodic table. And these elements should be diagonally adjacent pairs. These relationships are generated by the identical size of the ions. The atomic size decreases across the period due to the increasing in the effective nuclear charge. And the atomic size is decreasing across the group due to increasing the number of shells.

Complete answer:
As we know that the beryllium is present in the second period and the aluminum is present in the third period of the periodic table and both elements are metal. Hence, both aluminium and beryllium have the diagonal relationship. And that are,
Both beryllium and aluminum have the tendency to form covalent compounds.
The beryllium chloride and aluminum chloride are used as Friedal crafts catalysts. Because, both act as Lewis acids.
Both Be and Al will dissolve in the bases and there is a formation of complexes such as beryllates and aluminates.
The oxides of both are high melting insoluble solids and they are very hard.
The hydroxides and oxides of both metals are amphoteric in nature.
The carbides of beryllium and aluminum will react with water and there is a liberation of methane gas.

Note:
The diagonally adjacent pairs will show similar properties and are present in second and third periods of the periodic table. The aluminum is located diagonally opposite to the beryllium and it has some resemblance with aluminium. The diagonal relationship is attained by the identical size of the atoms. The size will be varying when the element moves from left to right of a period and top to down of a group according to their number of shells.