1. Identification of the metal X and the process responsible for the change:
The metal X in this case is copper. Copper is known to acquire a greenish coating on its surface when exposed to air for a certain period of time. This process is called oxidation, specifically copper oxidation.

2. Name and formula of the green coating formed on the metal:
The green coating formed on the surface of copper is known as copper oxide. The chemical formula for copper oxide is CuO.

3. Methods to prevent the oxidation process:
Oxidation of copper can be prevented by implementing various methods to protect the metal surface from exposure to air and moisture. Two important methods to prevent this process are:

a. Coating:
Applying a protective coating on the surface of copper can prevent it from coming into direct contact with air and moisture. This barrier will inhibit the oxidation process. Some common coatings used for copper protection include lacquer, varnish, or wax. These coatings form a thin film over the copper surface, acting as a barrier against oxidation.

b. Anti-oxidizing agents:
Using anti-oxidizing agents is another effective method to prevent copper from oxidizing. These agents react with oxygen and moisture in the air to form a protective layer on the copper surface. One commonly used anti-oxidizing agent is mineral oil. When mineral oil is applied to the copper, it creates a thin layer that prevents air and moisture from reaching the metal, thus inhibiting oxidation.

Explanation:
Coating the copper surface with lacquer, varnish, or wax provides a physical barrier that prevents direct contact between the metal and the air. This inhibits the oxidation process as oxygen and moisture cannot reach the copper surface. These coatings also add an aesthetic appeal to the metal, as they can be chosen to have a desired color or finish.

Anti-oxidizing agents, such as mineral oil, work by reacting with oxygen and moisture present in the air. This reaction forms a protective layer on the surface of copper, preventing further oxidation. Mineral oil is often used as it is readily available and has good anti-oxidizing properties.

Both coating and anti-oxidizing agents provide effective protection against oxidation of copper. However, it is important to note that these preventive measures may require periodic reapplication to ensure continued protection. Regular cleaning and maintenance of the copper surface are also essential to remove any existing oxidation and maintain its appearance and integrity.

》Metal X is copper

¤The process responsible for this is corrosion

》Green coating is copper dioxide (CuO)

》Preventive methods:

¤Painting

¤Greasing