Some elements and their valencies are given. Write the chemical formula of barium chloride.

Element	Valency
Ba	2
Cl	1
Zn	2
O	2

Hint :In chemistry, an element's valence or valency is a measure of its ability to combine with other atoms to create chemical compounds or molecules. An ionic compound is a chemical complex made up of ions kept together by electrostatic forces known as ionic bonding in chemistry. Overall, the chemical is neutral, although it contains both positively and negatively charged ions known as cations and anions.

Complete Step By Step Answer:
Ions with opposite charge are closely packed to create crystalline solids. When metals react with non-metals, ionic compounds are created.
Ionic compounds, in other terms, are ionic compounds kept together by ionic bonds. In order to achieve their closest noble gas configuration, elements can gain or lose electrons. The formation of ions for the completion of the octet (either by receiving or losing electrons) aids in their stability.
Metals lose electrons to complete their octet in a reaction between metals and nonmetals, whereas non-metals acquire electrons to complete their octet. Ionic compounds are formed when metals and nonmetals react.
The inorganic salt barium chloride is made up of barium cations ($B{a^{2 + }}$) and chloride anions ($C{l^ - }$). Barium muriate of barium chloride are other names for it. It's a white solid that's water soluble, hygroscopic, and gives a flame a faint yellow-green tint. $BaC{l_2}$is the chemical formula for barium chloride. In the industry, barium salts are widely used. White paints, especially for exterior usage, include sulphate. In nature, barium chloride is toxic.
${\mathbf{B}}{{\mathbf{a}}^2}{ \times ^1}{\mathbf{Cl}} \to {\mathbf{B}}{{\mathbf{a}}_1}{\mathbf{C}}{{\mathbf{l}}_2} \to {\mathbf{BaC}}{{\mathbf{l}}_2}$
The valency of Ba being 2 and Cl being 1, the compound being formed is $BaC{l_2}$.

Note :
Despite its low cost, barium chloride has just a few uses in the laboratory and industry. Barium chloride is primarily utilised in industry for the purification of brine solution in caustic chlorine facilities, as well as the creation of heat treatment salts and steel case hardening. Its usefulness is limited due to its toxicity.