12. what is the completed balanced reaction for the decomposition reaction shown below?
ag₂o ?
a. ag, ag, +
c. 2ag,0 - ag, o, + 0,
b. 2ag,0 - 4ag + o,
d. ag,0 - 2ag + o

2Ag₂O  →  4Ag + O₂

Explanation:

Chemical equation:

Ag₂O  →  Ag + O₂

Balanced chemical equation:

2Ag₂O  →  4Ag + O₂

The given reaction is the decomposition of silver oxide. The silver oxide is decomposed into its constituent element silver and oxygen.

Decomposition reaction:

It is the reaction in which one reactant is break down into two or more product.

AB → A + B

This reaction also followed the law of conservation of mass because there are equal number of atoms of all elements on both side of equation.

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by french chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.