When a silver-colored coin, like a penny coated with zinc, is heated, the zinc and copper (the primary metal in a penny) can mix to create a brass alloy . This brass alloy has a golden color, making the coin appear gold. [According to Brainly] , this process is called metal alloying.
Here’s a more detailed breakdown:
- Zinc Coating: A copper penny is often first coated with a layer of zinc, which gives it a silvery appearance.
- Heating: When this zinc-coated penny is heated, the zinc on the surface can diffuse into the copper, forming an alloy called brass.
- Golden Color: Brass is an alloy of copper and zinc, and depending on the proportions, it can have a yellowish, or golden, appearance. This is how a silver-looking coin can be made to look gold, [according to Instructables].
It’s important to note that this is not actually turning the coin into real gold, but rather creating a gold-colored alloy on its surface.
What change happened to make the silver coin look gold?
Surface Coating: The coin may have been coated with a thin layer of gold. This is often done through processes like gold plating, where a layer of gold is applied to another metal, giving it a gold appearance.
How did the mass change when the silver looking coin was made to look gold?
From my experience, When a silver coin is made to look like gold, its mass does not change significantly. This is due to the process of electroplating, where a thin layer of gold is deposited onto the surface of the silver coin. Although gold is denser than silver, the layer applied is very thin, meaning it adds very little mass overall.
How to make silver coins look gold?
To turn the silver color to gold we need to heat the coins at a considerable temperature, enough to melt the zinc so that it fuses with the copper, mixing their colors to create a shiny golden coin.
How was the matter of the coins changed to make them look silver and then gold?
From my experience, In this reaction, a penny is placed in a boiling solution of 1 M zinc chloride containing granular zinc. The penny develops a zinc “silver-colored” coating. When removed from the solution and placed on the surface of the hot plate, the brass alloy coating on the penny turns a golden color.