Beryllium shows diagonal relationship with aluminium. Which of the following similarity is incorrect? (a) \(\mathrm{Be}_{2} \mathrm{C}\) like \(\mathrm{Al}_{4} \mathrm{C}_{3}\) yields methane on hydrolysis. (b) Be like \(\mathrm{Al}\) is rendered passive by \(\mathrm{HNO}_{3} .\) (c) \(\mathrm{Be}(\mathrm{OH})_{2}\) like \(\mathrm{Al}(\mathrm{OH})_{3}\) is basic. (d) Be forms beryllates and \(\mathrm{Al}\) forms aluminates.

When studying the periodic table, the diagonal relationship is a fascinating phenomenon that illustrates similarities between certain pairs of diagonally adjacent elements. One of the most well-known pairs is Beryllium (Be) and Aluminium (Al). Although they belong to different groups, they exhibit several important similarities due to their diagonal positioning.

Beryllium, found in Group 2 (the alkaline earth metals), is the lighter element and has a smaller ionic radius compared to Aluminium, which is in Group 13 (the boron family). Despite these differences, their chemistries are surprisingly parallel. For instance, both Be and Al tend to form covalent compounds rather than ionic ones, which is atypical for their respective groups.

Furthermore, both elements can exhibit passivity when treated with strong oxidizing agents like HNO3, forming a protective oxide layer on their surfaces that prevents further reaction. This is largely due to their high charge density which facilitates the formation of this protective layer. They can also form bonds with carbon to produce compounds such as Be2C and Al4C3, which upon hydrolysis generate methane gas (CH4).

However, the comparison is not perfect; notable differences arise, particularly when looking at their hydroxides' chemical behavior, which will be explored further in the context of amphoteric hydroxides.

The chemical properties of elements are essential for understanding their behavior during reactions. These properties include how they react with water, acids, bases, and other compounds, and are influenced by factors such as electron configuration, electronegativity, atomic size, and the nature of chemical bonds they form.

For example, elements with similar electron configurations like Beryllium and Aluminium may exhibit similar reactivity patterns. They both react with water to produce hydrogen gas. Their reactivity with other substances such as acids or bases can show both parallels and contrasts due to the variations in their atomic structures and reactivity.

The periodic trends play a significant role in these chemical properties; for instance, as we go down a group, the reactivity of metals increases due to the increasing ease of losing electrons. In contrast, across a period from left to right, nonmetals become more reactive as gaining electrons becomes easier. Understanding these trends helps predict how elements might react under different conditions, which is critical in both laboratory chemistry and industrial applications.

Amphoteric hydroxides are a unique type of compound that can react both as acids and bases. This dual behavior is known as amphoterism and is particularly intriguing in the discussion about Beryllium and Aluminium.

Characteristics of Amphoteric Hydroxides

Amphoteric hydroxides, like Be(OH)2 and Al(OH)3, have the ability to neutralize both acids and bases to produce salt and water. Their amphoteric nature depends on the electron structure and the partial ionic character of the metal-oxygen bond in the hydroxide.

Be(OH)2 tends to react more readily with acids, showing a stronger acidic character, which sometimes leads to confusion when it's presumed to be solely a base. In contrast, Al(OH)3, also amphoteric, shows a stronger reaction with bases than acids, revealing a more pronounced basic characteristic. It is this variation in behavior that illustrates the subtle differences within diagonal relationships of the periodic table.

Understanding the concept of amphoteric hydroxides is vital as it applies to several fields including material science, pharmaceuticals, and environmental chemistry. It guides chemists in predicting the outcomes of reactions involving metals and helps in synthesizing new compounds with desired properties.