As Barium belongs to Group II elements (Alkaine Earth Metals), it has two valence electrons in 6 shell, Hence it capable of loosing two electrons and adopting +2 charge as,
Ba → Ba⁺² + 2 e⁻
And Chlorine belongs to Group VII elements (Halogens), it has seven valence electrons in 3rd shell, Hence it is capable of accepting one electron and adopting -1 charge as,
Cl + e⁻ → Cl⁻
Now, for the formation of Barium Chloride we need 2 chloride ions and one Barium cation, as two -1 and one +2 charge can add to form a neutral molecule. Hence,
Ba⁺² + 2 Cl⁻ → BaCl₂
Answer: The reaction does occur.
Explanation: For the reaction of aqueous strontium sulfide and aqueous copper(II) sulfate, the reaction follows:

This reaction is a type of precipitation reaction.
The precipitate formed is CuS which is black in color.
Answer:
Burning of the candle is both physical and chemical change. Burning of the candle melts the wax and hence physical state of wax has changed from solid to liquid.
Again the wax combines with the atmospheric oxygen and changes to carbon dioxide, heat and light.
Thus both the changes are accompanied by the burning of the candle.
Explanation:
hope this helps!
~mina
The person who discovered universal gravitation was newton.
When a metal undergoes a reaction, especially with a nonmetal, you should look for the formation of salts or the formation of precipitates in the case the product is not soluble to water. Metals loses electrons to form positive ions which then reacts to nonmetals that are negatively charged ions.<span />