Use social media to teach the development of the periodic table

Recent changes to GCSE chemistry specifications have placed increased focus on how scientific ideas and explanations develop over time as new evidence emerges. For example, the development of the modern periodic table. Analysing early versions of the periodic table is an interesting area of study; however, it can often be content heavy and difficult to emphasise to students what they need to know.

There is a wide array of online resources on the development of the modern periodic table, including the RSC’s Development of the periodic table, making it an excellent opportunity to develop pupils’ research skills. What I’ve found, however, is that without setting clear guidelines and objectives, there can be vast differences between what students produce from their research. While some develop lengthy stories and essays, others submit a few lines of poorly explained narrative which don’t quite link together. To combat this, I took a step back from the content and thought about how I could simplify the core ideas to help my students understand the importance of the scientific process without getting too overwhelmed. I wanted to present this in a format they are used to, and employ the use of clear, accessible language; hence Social media scientists was born.

Prior knowledge

Students will need to understand:

• Atomic structure: including the arrangement of subatomic particles in an atom
• The current layout of the periodic table, including the meaning of ‘mass number’ and ‘atomic (proton) number’, and the arrangement of elements in groups and periods

While the latter could be covered in subsequent lessons, students pick up on the problems with each model more if they understand why they don’t ‘fit’ with our current understanding of elements.

Lesson structure

Following a quick recap on the key concepts of atomic structure, I discuss the current layout of the periodic table with my students. I make sure to highlight key ideas such as:

• Elements are placed in order of atomic (proton) number
• The arrangements of elements in groups of similar properties
• Elements in the same group have the same number of outer-shell electrons

We discuss whether the periodic table has always looked like it does today, and possible reasons behind this. This is a good opportunity to recap the discovery of the atomic model. Protons, neutrons and electrons were all discovered at different points throughout history, so scientists may not have been aware of the three key points above when developing their periodic tables.

I then introduce the activity to my students: they must develop social media profiles and posts for each scientist who contributed to the development of the modern periodic table. This usually creates a buzz of excitement in the room!

The following lesson, we come together to review the social media profiles and posts they’ve created. We discuss why some models didn’t work for all elements and why new ideas needed to be developed. The remainder of the lesson can be spent practicing exam-style questions linked to the topic.

How it helps

The main benefit of this activity is that it frees up lesson time to discuss the ‘hows’ and ‘whys’ rather than the more accessible ‘whats’. Rather than fact learning, we focus on comparisons, evaluations and explanations, allowing me to offer guidance to my pupils rather than simply delivering content. This has really helped to improve the quality of my students’ answers to exam-style questions. Having the opportunity to practice and refine their technique after receiving instant feedback is a much more meaningful use of our lesson time.

The task additionally allows us to focus on the scientific process. More able students tend to pick up on ideas of why previous models failed or didn’t fit for all elements in their tweets, often using the tweet platform to ‘call out’ other scientists and their models. While this provides an element of humour to the lesson, it also helps us focus on how each model built upon the ideas of others.

Condensing the information into bite-sized chunks has aided my students in their revision too. Rather than ploughing through lengthy notes, the information they need is summarised in a visual, easy-to-digest resource which they can refer to when applying their knowledge to exam-style questions.