Which of the following is a property of Beryllium?

Forms covalent compounds

The correct answer is option 4. Forms covalent compounds.

Beryllium is a metal that exhibits unique properties, and one of them is its tendency to form covalent compounds. Here's an explanation:

1. Electronic Configuration:

Beryllium has an atomic number of 4, and its electronic configuration is \(1s^22s^2\). It has two valence electrons in the \(2s\) orbital.

2. Small Size and High Charge Density:

Beryllium is a relatively small atom with a high effective nuclear charge due to its low atomic number. The small size and high charge density of beryllium make it more likely to share electrons in covalent bonds rather than lose electrons to form ionic compounds.

3. Tendency to Form Covalent Bonds:

Beryllium tends to exhibit covalent bonding characteristics, particularly in compounds where it can achieve a stable electron configuration by sharing electrons. It often forms covalent compounds, especially with nonmetals like oxygen and fluorine.

4. Example: Beryllium Oxide (BeO):

Beryllium oxide (BeO) is an example of a covalent compound formed by beryllium.

In BeO, beryllium shares electrons with oxygen, resulting in a covalent bond.

\[ \text{Be} + \text{O} \rightarrow \text{BeO} \]

5. High Melting and Boiling Point:

Contrary to the statement in the options, beryllium generally has a high melting and boiling point. This is attributed to its strong covalent bonds, which require a significant amount of energy to break.

In summary, beryllium tends to form covalent compounds due to its electronic configuration, small size, and high charge density. Beryllium oxide (BeO) is a notable example of a covalent compound formed by beryllium.