Improving Cambridge IGCSE Chemistry practical skills from home

Michael Strachan

Teaching remotely presents challenges for all teachers, however, when you teach a practical subject these challenges are naturally multiplied. As an advocate of practical work forming the core of any science lesson, it was imperative that I found ways to ensure that key investigative skills needed by my students were developed even though practical work in the traditional sense might not be possible.

My starting point was to review all of the assessment objectives from the specification that related to investigative and practical work to identify which aspect I could still deliver, albeit remotely. The four key areas chosen were planning, collecting data, handling data and interpreting data. 


Students need to be able to plan safe and effective investigations but this skill is probably one of the least practised. Fortuitously students can hone their planning skills without the need to actually carry out the investigations. Good examples to use for students can be found in the alternative to practical paper. These questions can be used to structure planning practice. During remote learning these questions can be shared on screen so students can offer their answers live or sent as independent tasks, which are then marked by the teacher. By getting students to review their own and others’ work with reference to examination mark-schemes their understanding of the essential elements of an investigation can be enhanced. To develop deeper thinking, you can challenge students to create their own exam-style questions and mark schemes, which they can share with classmates for extension work. There is, of course, always the opportunity for the teacher to create questions of this type, incorporating local context as well, which works well to engage students.

Collecting data

There are two ways that students can still collect data while studying from home. The first is by conducting home investigations, the second is by conducting virtual experiments. Although home investigations do reinforce practical skills and add to student engagement there are some downsides. Foremost is student safety as it is not possible to ensure that students are working safely or being supervised. There is also an argument for equity of access as not all students will have access to the same resources which means that some students may not be able to take part.

It is still possible to assign students practical investigations to complete at home, all that is needed is some creative thought. By suggesting simple investigations with very little equipment it is still possible to give students practice collecting data. Some simple home investigations that do not pose safety issues and are accessible to all students are listed below:

– What affects how many drops of water can be added to a coin?
– What affects how much salt will dissolve in water?
– What affects evaporation rate?
– What affects the melting temperature of ice?

Virtual experiments are also a useful technique to get students collecting data; there are software packages that you can purchase but also free examples too. My personal favourite is PhET from the University of Colorado, which is free to download.

Handling data

In terms of handling data, focusing of students’ mathematical skills is always worthwhile. I find giving students data and having them practise plotting graphs improves their confidence when faced with graph questions. Students can practise plotting graphs from either the data they generate virtually, or data provided by the teacher. Giving structure is helpful so my students use a checklist of items they must include in graphs to help guide them: scale, label, axes, plot, units and key. Make sure you familiarise yourself with the specification and exam mark schemes for graph questions as the guidance is invaluable.

Interpreting data

The final skill I have been focusing on with my students has been interpreting data, principally from graphs. Many students struggle with the difference between the command words ‘describe’ and ‘explain’. I often use graphs from non-chemistry-based sources, which force the students to simply describe the pattern of the graph as they do not have any ability to explain.

In summary, it is possible to develop the knowledge and skills needed for students to be successful scientists even when teaching remotely. All that is needed is careful planning and resourcing with a sprinkle of imagination. I have used the support material freely available from the syllabus for much of the work I have done.

Watch Michael’s webinar on Cambridge IGCSE™ Chemistry – Improving their practical skills from home: 

You can view Michael’s presentation from the webinar here.

Frequently Asked Questions from the webinar with answers from Michael Strachan

Is it safe to do practicals from home?
It depends on the practical – I have included some very simple examples in the blog and presentation.

Is doing past papers enough?
I do not think so. Using past papers, in my experience, does not develop a deep understanding by students and they will struggle to answer questions in a novel context.

How to teach with PhET
I set an investigation and the students would use PhET to collect the data needed. I would always direct them to the simulation to use.

What advice to give Cambridge IGCSE learners who are moving onto A Level about practicals
Familiarise themselves with the new aspects of practical skills they will need for A Level. Here are some practical workbooks that they could use to give them a head start.

How to improve students on the error and improvement question in ATP
Practice! Get them to review lots of investigations and suggest improvements. Realistically there are only so many improvements that can be made to improve accuracy or reliability. If students are aware of these then they should be able to suggest improvements.

Ways to help students reflect on a concept in practical work
Getting students to evaluate their practical work or other investigations.

Share one common struggle of your students doing practical work at home and how you helped them
I have generally used virtual experiments as opposed to practical work at home but I found that students lacked equipment, so I developed simple practicals that required little apparatus.

How do you record a student’s understanding of a practical concept
I have used the CI practical skills (AO3) and created a grid and then I check off as I observe each student demonstrate each skill.


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