Growing a chemistree and a competition -cover article

When I first encountered a chemistree as a new teacher, I thought it was brilliant and naively, a new idea. I soon learned that this idea had been around forever — like so many other ideas. Last year Twitter helped me discover more chemistrees through an online competition called ochemistree1 organized by John O’Donoghue from the School of Chemistry at Trinity College Dublin, Ireland. If you thought you had seen all the possible variations of chemistrees, well, trust me, you haven’t. 

I recommend a visit to John’s blog dedicated to his informal competition showcasing a collection of past and present chemistrees. The aim of the competition is to help other chemists design, innovate and have fun with chemistry themed Christmas trees! It begins on the 7th of December every year. Best news is that to enter, you just tweet with #chemistree and @johndhodonoghue.2

John has been doing this informal competition for years. He started “judging” chemistrees for fun on Facebook during his PhD — he admits to it mainly being a distraction from doing real work. Over the years, he has transferred the competition to Twitter with hashtag #chemistree with the result of bringing the chemistry community together to share their creativity.  

A true scientist, John has classified chemistrees into five categories for the competition. 
1.    Paper based tree: 2D drawings/graphics  
2.    Chemified tree:  adding chemistry items to an existing Xmas tree 
3.    Cross-over tree: using tinsel or other traditional Christmas Tree items with lab equipment such as retort stands and glassware
4.    The Purist Chemistree: using solely lab-based materials, such as retort stands, glassware and other equipment. The purists may also prefer to use fluorescent baubles for lighting up their creation! 
5.    Grown (crystals), nanoscale or molecular modelling: no explanation necessary.

We at Chem 13 News got a mention for our paper trees and the tiniest tree.

Christmas tree made out of retort stand, clamps and round bottom flasksA colour-by-numbers (solutions colour) in December 2016 - January 2017 issue. 



a retort stand with different lab equipment shaped like a Chemis-treeA chemistree made from high school lab equipment, front cover December 2015 -January 2016 issue. (Have students name all the equipment, no repeats.)

Chemis-tree under a coverslip on a microscope slide

littlest chemistree of made of a triangle of copper with black colour branches upclose under a microscope The littles chemistree made with a triangle of copper on a microscope with a drop of silver nitrate, front cover of December 2016 - January 2017 issue.

On the blog John writes that last year: “Was by far the busiest I’ve seen with the theme of innovation, spurred on by some new friends at Chem 13 News based at the University of Waterloo in Canada, as well as the Royal Society of Chemistry in the UK and many more chemistry colleagues dotted all over the world. A huge thank you to everyone for making the #chemistree hashtag so popular this year and thank you for sending me your wonderful creations!” 

The chemistree on our cover is the 2017 winner, tweeted out by William Barron de Burgh, a teacher at Gordon’s School, West End, UK. Not only is it beautiful, William captured a time lapse video of the growing tree. The 30-second mesmerizing video3 went viral. It is a must watch for you and your students.

a hand holding a small vial with a little silver Christmas tree

Screenshot of Twitter feed with a small silver chemistry from Gordon Science

From our Chem 13 News archives 

Out of curiosity, I did a little digging into our archives to our first mention of a chemistree. The first iin our magazine was over four decades ago and is strikingly similar to the 2017 winning chemistree from John’s competition — except for the size and video. For your enjoyment, we have reprinted these finds. Unfortunately in the ’70s, our magazine did not contain colour photos.

Replacement of silver by copper

Reprint May 1976

Agnes Hunt
Birmingham Board of Education
Birmingham, Alabama

Perhaps the most striking aspect of the activity series is the actual displacement of one metal by another from its compounds.

copper wire tree showing silver nitrate crystals growing on it

Fashion a little tree from a copper wire and suspend it in a solution of silver nitrate (this is especially effective around Christmas time). See the diagram. In a short time silver will begin to be deposited on the wire as it is replaced in the solution by copper. It is readily apparent that the deposit is silver because of its white metallic appearance which will form a very beautiful “tree” overnight, and it is also apparent that the copper has gone into solution because it becomes blue. Unfortunately, the tree cannot be removed intact from the solution; the silver deposit will fall off.


Reprint October 1976

Bea Paige and Ingrid Merrill
Antelope Valley College Lancaster, Pennsylvania

The week prior to the Christmas vacation is a very restless one for students. In an attempt to make the chemistry lab more interesting, we have adapted a special version of a copper-silver replacement reaction as follows. 

black and white chemistree with beadsAn inorganic chemis-tree?

In the bottom on a Petri dish we place the outline of a Christmas tree formed out of copper wire. Over that we pour a solution of silver nitrate which just covers the wire. While the replacement reaction is proceeding, we make colored beads to trim the tree using the borax bead test. A tiny loop is bent over a pencil in one end of a piece of nichrome wire. The other end is inserted into a cork to act as a handle. The wire is heated to red-hot in the Bunsen burner flame before filling the whole loop with borax (Na2B4O7•10H2O). Then it is returned to the flame until the borax melts and forms a clear bead filling in the loop. Different colors are produced by dipping the hot, clear bead into miniscule amounts of various powdered metal salts and reheating until the bead is evenly colored. After each bead is completed, the loop is cut off, leaving the wire long enough to attach the bead to the branches of the tree. Plastic forceps are used and care is taken not to disturb the beautiful silver crystals. Some metallic salts which we find give good borax bead results are salts of cobalt, iron, chromium and manganese which give, respectively, blue, light green (iron and chromium) and violet beads. We find that very dark salts don’t work well. The cobalt salts give the beautiful famous cobalt blue color.

[Editor’s note: Like all activities, especially ones from the ’70s where safety procedures were not included, safety needs to be reviewed.]

Some students use their copper wire to write messages, such as Merry Christmas, before immersing the wire in the silver nitrate solution. The project can be used at any season by forming the wire into other shapes such as a rabbit (Atomic Bunny), a cat (Cat-ion), a pumpkin or a Santa Claus. To add color, the Petri dish can be backed with construction paper of an appropriate color. The silver crystals are very fragile but may be preserved by embedding the finished design in casting resin after all the liquid has evaporated.

For children, the plaques can be finished as a gift by simply affixing adhesive-backed hooks for hanging, or more elaborately by framing it in a circle of Styrofoam. (Styrofoam can be cut with a hot knife.) 


Reprint December 1976

chemistree in black and white made out of lab equipment with a retort standConstructed by Grade chemistry class at Chapleau High School, Chapleau, Ontario.

References and notes

  2. Be inspired and tweet your chemistree — we would love if you included us in your tweet @chem13news. We are always interested in more creative chemistrees. Feel free to email us photos for next year’s holiday issue!