Craft festive molecular baubles

It’s almost that time of year – the last week of term before the festive break. The students are already exclaiming, ‘we’re only playing games and watching films in other lessons.’ They’re probably ready for a break from the curriculum, and it’s likely you are too. But how can you infuse a bit of festive fun into the last week of term? 

With molecular baubles. They’re the perfect way for students to take an element of festive science home to their families. It’s all thanks to classroom chemistrees that I came up with this idea.

Crafting molecular baubles came at a perfect time with my year 7 students. They had completed the fundamental atoms, elements and molecules unit in their first term at secondary school and grasped simple formulas like O₂, H₂ O and CO₂. For year 8 and 9 classes, the baubles presented an ideal retrieval activity, reiterating the difference between atoms, elements, molecules and compounds.

To get the most out of this activity, you need to establish learning objectives at the beginning of the lesson. They could be:

• identify which elements are in a molecule;
• specify how many elements of each type are in a molecule; and
• describe the difference between a molecule and a compound.

Begin the lesson with a starter activity recalling the formulas of simple molecules such as water, carbon dioxide and oxygen. Ask students to then identify which are elements and how many are in the molecules. Prompt students to justify their answers, asking them to describe what an element is and how that differs from an atom. You could challenge students by displaying more complex (or even festive) molecular formulas such as sucrose, rudolphomycin or alpha-pinene. Ask whether these are molecules or compounds and why they think that.

Consider the practical side

As the molecular models will be hanging from a tree, you need craft materials that produce a robust bauble – something up to the trip home in a schoolbag. I chose compressed cotton balls of several different sizes to represent various elements. Felt-tip pens are an excellent option to decorate the baubles as the ink dries quickly and glue dots work brilliantly as an adhesive to instantly join atoms and ribbon. You could use matchsticks to represent bonds between atoms, but this will create more fragile baubles. All these items are inexpensive and easy to order online – or you could raid the art department.

After the starter activity, follow these steps with your students:

1. Cover the desks with newspaper to prevent ink stains on surfaces.
2. On the board display example molecules and write which colours represent each element.
3. Let students choose their molecule, then encourage them to sketch the element symbol and their designs on the balls in pencil.
4. Students can now decorate their atoms in festive patterns or solid colours using the felt-tip pens (warn students not to touch wet ink).
5. Guide students to use the glue dots to bond their atoms and ribbon together. I demonstrated this step using a visualiser, telling students to use glue dots similarly to double-sided tape.
6. I found writing some of the steps on the board helped students to work independently.

While they are crafting, remind the class they are responsible for cleaning up their own mess. One of my students disintegrated a ball and scattered the remains on the classroom floor. Consequently, he spent his break time honing his sweeping skills.

As with all modelling activities, there is a chance for misconceptions to creep in. A common misconception is that molecular models replicate the real thing and that atoms really are small, coloured balls. To tackle this, circulate the classroom and ask diagnostic questions such as ‘how do you think your model of a molecule is different from real molecules?’.

Most of all, enjoy this time with your students. Background music during craft time always creates a festive atmosphere in their last science lesson of term.