Homeschooling with MEL Chemistry: Making a Tin Hedgehog

Tin Hedgehog

Once a week, on a Tuesday afternoon, Abigail and I get together and do some science together. Usually it is from a company called MEL Science, with whom we have a monthly subscription (Abigail’s Christmas present this year). The first activity we did was to grow a tin hedgehog.

Making a Tin Hedgehog: The Box

Abigail is sent one box per month which contains at least two different experiments, with absolutely EVERYTHING included that you need to carry out the experiments (more than once, should you wish to!):

Each box is themed (click on the link to see all the available MEL science chemistry kits). For example, Abigail’s first box was tin themed, and both experiments used the properties of tin – in this case to grow a tin hedgehog (tin creates spiky crystals, which look hedgehog-like!) and growing tin trees in a petri dish, again using the dendrite appearance of tin crystals which form when an electric current is passed through a solution of tin chloride. Today, I will be sharing photos of Abigail making her tin hedgehog.

Tin Hedgehog: Preparation

To prepare for each experiment, I first have Abigail watch the video supplied by MEL Science (all MEL science experiments). The company provides simple experimental videos, along with instructions on how to carry out the experiment; safety aspects related to the particular experiment; Step by step instructions; expected result; an easy to follow scientific explanation of exactly what is happening and suggestions for further study. Abigail watches and reads through the entire Tin Hedgehog information page.

Afterwards, she gets everything she needs to do the experiment ready, along with all her safety equipment (goggles, lab coat, gloves etc):

Tin Hedgehog: Method

In addition to the instructions online, MEL Science also provide a small easy read, step-by-step card with diagrams, to enable the students to be as successful as possible.

  • Abigail poured the bottle of sodium bisulphate into the bottle containing tin chloride:
  • And gave it a good shake:
Tin Hedgehog
  • Abs added the mixture to the small container provided until it was half full:
Tin Hedgehog
  • I smiled as I watched her instinctively know to look at it at eye level:
  • She emptied out a small piece of Zinc:
  • And placed it gently into the container with the solution:
  • The watching began! Abigail has placed the macro-lens (supplied by MEL Science) onto her kindle camera to enable her to take close up photos:
  • There was enough solution left to do a second container, so about ten minutes after the first tin hedgehog was begun, she started another one:
  • The crystal growing happened much slower than I thought it would:
  • But it did happen:
Tin Hedgehog
  • The one on the left was the one Abs did first. The crystals are super fragile and we had just jogged the table and they broke off, floating at the top of the container:

Tin Hedgehog: Results

This was ten minutes after the zinc nugget was dropped in:

Twenty minutes after:

Thirty minutes after:

Tin Hedgehog: What is happening?

I was going to just link you back to the MEL science website, because they explain it so well. However, I decided to snip a small section of it, because I think it is explained so well and in an easy to understand way. I tell you, if I had learnt chemistry this way, I might have understood some of it!


For the rest of the explanation along with chemical equations do pop over to their experimental page.

Tin Hedgehog: Explaining it to Someone Else

It is a good test to see if a student understands something by listening to him or her explain it to someone else. Big brother was the perfect person to do this to, as he is scientifically minded and understood exactly what she was talking about:

Tin Hedgehog: Further Exploration

MEL Science include a separate section entitled ‘Follow up’. There is also a great periodic table wbsite, where Abs could explore further the chemicals she was using. Abigail spent some time on her kindle reading up a bit more on Tin:

Tin Hedgehog

I’ll be posting about Abigail’s ventures making a tin dendrite tree next 🙂

Related Posts

All science posts


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.