Answer: [tex]BeCl_2[/tex]
Explanation: For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here beryllium is a metal and can lose 2 electrons to form a cation and chlorine can accept one electron to form an anion.
[tex]Be:4:1s^22s^2[/tex]
[tex]Be^{2+}:2:1s^2[/tex]
[tex]Cl:17:1s^22s^22p^63s^23p^5[/tex]
[tex]Cl^-:18:1s^22s^22p^63s^23p^6[/tex]
The cations and anions being oppositely charged attract each other through strong coloumbic forces and form an ionic bond.
[tex]Be^{2+}+2Cl^-\rightarrow BeCl_2[/tex]
