Reactivity of metals
Atoms of reactive metals tend to give up electrons very easily to other less reactive metal atoms when placed in contact with each other. Very reactive metals are never found in pure form in nature. They are so reactive that they react with oxygen and water to produce different compounds. Sodium is an example of a very reactive metal that reacts quickly with water to produce hydrogen gas and heat. Gold on the other hand is not very reactive and does not readily give up its electrons to react with other substances. Gold is therefore found in pure form in nature.
|Silver atoms, dissolved in water, will take electrons from a more reactive metal, such as copper, and precipitate out of solution. Consider the animation on the right, it shows a time lapse of copper metal placed in a solution of silver nitrate.|
|Silver ions floating in the solution approach the copper metal where they take electrons and form solid silver. Copper atoms which have lost electrons dissolve in the water.|
The fact that electrons flow from reactive metals to less reactive metals is the basis of the modern day battery. Electrons are forced to flow from one metal to another via a wire. As the electrons travel through the wire they are forced to travel through items such as light globes and radios and do useful work for us.
A sample of silver solution is found. Jonathon decides to recover the silver by placing a metal in the solution. He has a piece of copper and gold. Which metal should he use. Explain how the silver will be recovered.
Copper is commonly used around the home and is one of the least reactive metals. It will react with most other metals to take their electrons.