What’s the formula for barium chloride?

BaCl2

Explanation:

Barium is listed under Group 2A of the Periodic Table. Looking at the column, Barium is Ba. The elements listed in Group 2A have a charge of +2.

So we have Barium as Ba+2

Now let's move to Chloride. Don't bother looking at the table, because it is not listed. Chloride is an ion of Chlorine, which is from Group 7A and we know anything in that column has a charge of -1. So Chlorine has gained an electron and becomes Chloride. Note that this is an anion and has a negative charge. You can see how easy it was to change the name, you just change the suffix to -ide.

So we have Chloride as Cl−

We're not finished though! The charges do not balance!

To balance it we simply add another Chloride so that you have two negatives balancing the two positives. You'll write it as Cl2.

Now they balance; you have one barium Ba+2 and two chloride Cl− Cl−

The final formula is written as BaCl2.

Hope that helps!

BaCl₂ It is one of the most common water-soluble salts of barium. Like most other barium salts, it is white, toxic, and imparts a yellow-green coloration to a flame.