Answer:
2 electrons
Step-by-step explanation:
Barium is present in group two. It is alkaline earth metal.
It has two valance electrons. In order to achieve noble gas configuration it loses its two valance and get complete octet.
Electronic configuration:
Ba₅₆ = [Xe] 6s²
When it loses two electron it get configuration of xenon.
Chemical properties of barium:
It form salt with halogens.e.g
Ba + Br₂ → BaBr₂
IT react with oxygen and form oxide.
2Ba + O₂ → 2BaO
this oxide form hydroxide when react with water,
BaO + H₂O → Ba(OH)₂
With nitrogen it produced nitride,
3Ba + N₂ → Ba₃N₂
With acid like HCl,
Ba + 2HCl → BaCl₂ + H₂