The ionic compound of beryllium and chlorine is beryllium chloride, with the chemical formula BeCl₂. Here's why:

* Beryllium (Be) is a Group 2 element, meaning it has a +2 charge as an ion (Be²⁺).

* Chlorine (Cl) is a Group 17 element, meaning it has a -1 charge as an ion (Cl⁻).

To form a neutral compound, two chloride ions (2 x -1 = -2) are needed to balance the +2 charge of the beryllium ion. This results in the formula BeCl₂.