This is due to the process of corrosion or tarnishing. In this process, the metals reacts with elements in the environment like oxygen, carbon or sulphides to form hrdroxides, oxides, sulphides or carbonates. These compounds formed are dull and responsible for the loss of the shinny nature of the vessels.

Some metals often lose their shine and appear dull, because of the action of air and moisture on them. Some metals as a result of oxidation with the atmospheric oxygen form oxides and by which their appearance becomes dull.

Answer : Iron articles lose their shine gradually when exposed to the atmosphere. Iron is a reactive metal and when exposed to the atmosphere it reacts with atmospheric oxygen and moisture to form an iron oxide, commonly called rust.

some metals lose their lustre when left in the open for some time because oxidation occurs. this lustre can be restored by preventing the contact of water molecules on the metal.

Luster is an optical property of minerals. There are two main types of luster, metallic and nonmetallic, with an intermediate luster of submetallic. The intensity of the luster depends upon the amount of light reflected from the surface, which is generally related to the refractive index of the mineral.

silver react with the sulphur in air and becomes silver sulphide which is black in colour so the shine is lost…… …

Though aluminium is a highly reactive metal, it is resistant to corrosion. This is because aluminium reacts with oxygen present in air to form a thin layer of aluminium oxide. Because of this layer surface of alluminium turns into dull colour after some few days.

Explanation: The copper object loses its shine after some time is due to the formation of the copper oxide layer on them. When a copper object reacts with damp air, CO2, and water. It forms a green coating of basic copper carbonate on the surface of the object.

Answer. A) Silver and copper undergoes corrosion which results in formation of silver. sulphide as silver reacts with atmospheric hydrogen sulphide and copper forms basic copper carbonate when reacts with atmospheric gases.

Corrosion is the process of slow eating away of metal due to attack of atmospheric gases on the surface of metal resulting into formation of compounds such as oxides, sulfides , carbonates etc is called as corrosion. Rust is hydrated ferric oxide . Thus iron loses electrons and get converted to rust and lose its shine.

Here are some ways where we can prevent rusting :

1. Paint it – Paint the metal with any durable acrylic paint.
2. Keep moisture at Bay – Avoid contact with water or moisture.
3. Coat it with Oil – Use of oil or grease significantly reduces the chances of developing rust in iron.

5 Different Types of Corrosion Prevention Methods

1. Barrier Coatings. One of the easiest and cheapest ways to prevent corrosion is to use barrier coatings like paint, plastic, or powder.
2. Hot-Dip Galvanization.
3. Alloyed Steel (Stainless)
4. Cathodic Protection.
5. EonCoat.

Corrosion can lead to the loss in purity of the metal. Some important properties of the metal might also be lost due to corrosion. For example, the sturdiness of iron is lost when it undergoes rusting and the rusted iron crumbles easily.

The Most Corrosion-Resistant Metals for Your Equipment

• Galvanized Steel. Galvanized steel is not as resistant as some other metal types: only one coated layer of zinc works to prevent corrosion in this case.
• Aluminum. Aluminum has the power to create its own protection against corrosion.
• Red Metals.

Copper and copper–nickel alloys – an overview CuNi alloys are amongst the most corrosion-resistant materials. They resist humidity, non-oxidising acids, caustic and salt solutions, organic acids and dry gases like oxygen, chlorine, hydrochloric and fluorochloric acid, sulphur dioxide and carbon dioxide.

Also, aluminum is unique because it’s one of the few materials that are naturally corrosion-resistant. This material contains little to no iron so it cannot rust, though it can oxidize.

Grade 316 stainless is the one to use in harsh marine environments. Its nickname is “marine grade” for a reason. It contains 18% chromium but has more nickel than 304 and adds 2-3% molybdenum. This makes it more resistant to salt.