Transmutation

• Do not allow chemicals to come into contact with the eyes or mouth.
• Keep young children, animals and those not wearing eye protection away from the experimental area.
• Store this experimental set out of reach of children under 12 years of age.
• Clean all equipment after use.
• Make sure that all containers are fully closed and properly stored after use.
• Ensure that all empty containers are disposed of properly.
• Do not use any equipment which has not been supplied with the set or recommended in the instructions for use.
• Do not replace foodstuffs in original container. Dispose of immediately.

• In case of eye contact: Wash out eye with plenty of water, holding eye open if necessary. Seek immediate medical advice.
• If swallowed: Wash out mouth with water, drink some fresh water. Do not induce vomiting. Seek immediate medical advice.
• In case of inhalation: Remove person to fresh air.
• In case of skin contact and burns: Wash affected area with plenty of water for at least 10 minutes.
• In case of doubt, seek medical advice without delay. Take the chemical and its container with you.
• In case of injury always seek medical advice.

• The incorrect use of chemicals can cause injury and damage to health. Only carry out those experiments which are listed in the instructions.
• This experimental set is for use only by children over 12 years.
• Because children’s abilities vary so much, even within age groups, supervising adults should exercise discretion as to which experiments are suitable and safe for them. The instructions should enable supervisors to assess any experiment to establish its suitability for a particular child.
• The supervising adult should discuss the warnings and safety information with the child or children before commencing the experiments. Particular attention should be paid to the safe handling of acids, alkalis and flammable liquids.
• The area surrounding the experiment should be kept clear of any obstructions and away from the storage of food. It should be well lit and ventilated and close to a water supply. A solid table with a heat resistant top should be provided
• Substances in non-reclosable packaging should be used up (completely) during the course of one experiment, i.e. after opening the package.

Wait a little longer. Double-check to make sure that the coin is resting on the zinc wire. This experiment requires direct contact between the zinc in the rod and the copper in the coin!

This can happen, but it won’t interfere with the experiment! Your coin will still turn silver.

Whatever you do, don’t touch the coin and the rod without gloves. There may be some pollutants on the surface of the coin. Try carefully cleaning the coin again, or just use another coin.

If the coin has not changed colors at all, gently move the coin closer to the area above the flames and wait 5–15 more minutes.

The coin should turn golden after it is cooled and washed.

Don’t worry! Just continue the experiment.

It is well known that most metals conduct electricity well. In fact, electrical current is a flow of charged particles. The term ‘electrical conductivity’ is used to define matter’s ability to pass electrical current through itself. The electrical conductivity of metals is directly related to their atomic structure. Metals’ thermal conductivity, ductility (the ability to easily change shape while preserving integrity), and even metallic luster all result from their structural features, as does electrical conductivity.

A piece of metal can be thought of as a green field filled with fresh, dense grass and populated with ambling sheep. The sheep represent electrons, and the field represents positively-charged metal ions arranged in a certain order inside this piece of metal. However, all metals are different. For instance, compare copper’s and zinc’s crystal lattices (i.e. the order that their ions are arranged in). From the “sheep’s” (or electrons’) perspective, copper is a more pleasant “field” than zinc because the grass there is greener, tastier, and denser. Analogically, electrons are more attracted to copper ions than zinc ions. This explains an amazing phenomenon that happens when the two metals come in contact with each other: some electrons from zinc transfer into copper. No wonder: the grass is juicier there!

In our experiment, the electron transfer from zinc to copper leads to the zinc wire acquiring a positive charge and the copper coin acquiring a negative charge. When heated, the fraction of electrons that “defect” to the copper coin only increases. However, both the copper coin and the zinc wire are surrounded by the zinc salt ZnSO₄ solution, not just by water. In the solution, this salt dissociates into ions:

ZnSO₄ ↔ Zn²⁺ + SO₄^2-

Now let's consider the situation from the perspective of positively-charged zinc ions. We have both the positively-charged zinc wire and the negatively-charged copper coin. Naturally, a positively-charged object is attracted to a negatively-charged one. Therefore, the ions are happy to settle on the coin’s surface and accept the excess of electrons.

This forms additional “free lush meadows” on the coin, making the electrons from the zinc wire even more attracted to the coin. And at a certain point, there are no longer enough electrons for all zinc atoms in the wire, so the atoms on the surface finally turn into ions Zn²⁺. They may then leave to enter the solution.

Therefore, as a result of heating, the zinc atoms move from the wire onto the coin “traveling light”: they pass through the solution in the form of ions Zn²⁺, and their “electronic luggage” delivers itself separately, through the metals’ surfaces.

Gradually, the zinc atoms cover the coin completely, and the coin’s color becomes exactly the same as that of the zinc wire – all we can see on the coin’s surface is zinc!

The same result is obtained if zinc powder is dissolved in a solution of sodium hydroxide. Due to zinc’s amphoteric nature, it can react with both acids and bases. The reaction is:

Zn + 2NaOH → Na₂ZnO₂ + H₂↑

As you can see from the following video, zinc plating from such a solution also works well.

Let's take a roundabout approach to the subject. What is temperature? This property seems obvious enough in terms of our everyday experience: we can easily determine whether an object is cold or hot to the touch. Actually, temperature is an important parameter that reflects the speed of atoms and molecules. Particles begin to move faster when a substance is heated, and slow down when a compound is cooled.

The same thing happens with the coin in the experiment. When heated, the zinc atoms on its surface and copper atoms inside it begin to move actively. As a result, the zinc “sinks” into copper and thus permeates into the coin. Eventually, the coin’s surface comes to consist of a combination of zinc and copper atoms. When the atoms of the different metals alternate within one crystal lattice, an alloy is formed, in which one metal is dissolved in another. One such example is an alloy of copper and zinc, which is called brass.

Now, recall the structure of any metal. In our alloy, ions of zinc and copper are surrounded by a common “flock” of electrons. Thus, the color of the resulting alloy is a blend of silvery and reddish-brown, i.e. golden.