Science is the Way of Thinking

Many great minds over the years have argued that science is a way of thinking, and one of the most important things in it is to never stop asking questions.

In St. George International School and Preschool, we believe that practice, patience and dedication will lay the necessary carpet of knowledge for the bright and successful realization of our students. Biology, Chemistry and Physics are an integral part of the natural sciences, and seeing our children constantly upgrade their knowledge and keep asking themselves /us questions makes us extremely proud and inspired for what comes next.

The laboratory practices in biology in the recent weeks have unlocked new knowledge for students in the following areas:

Digestive System

In 6th grade this week, students successfully complete the topics on the digestive system, nutrients and a healthy lifestyle. As a good way to negotiate, the student from 6.B class, Rosi Kancheva, had prepared a project for the digestive system, thanks to which she managed to charm everyone in the department.

Cell Structure

The IGCSE syllabus covered a lot of information about cell structure in this lesson. Year 8 students used microscopes to examine potato tissue to observe both the potato cells and the starch grains that are found inside. To highlight the starch grains iodine solution was added and this turns the starch grains pale purple through to dark blue depending on the concentration of iodine.

The Enzyme Catalase

The AS syllabus covered enzymes and which factors affect enzyme activity. In this experiment students used cylinders of potato as their source of catalase and changed the concentration of hydrogen peroxide, the substrate to investigate its effect on catalase activity. In this case the results turned out as expected with the enzyme activity reaching a maximum and leveling off at a particular substrate concentration. Students needed to be careful using the more concentrated hydrogen peroxide since it is a powerful bleach and can damage the skin, eyes and also clothes.


The A-level syllabus in Year 12 covered photosynthesis and in one experiment students were expected to make an extract of chlorophyll from spinach leaves and then run samples of the chlorophyll through a chromatogram using a specific solvent. When completed students should be able to identify at least 5 different pigments that make up the green chlorophyll in leaves such as spinach leaves. These pigments work together to harvest light from the sun to create sugars such as glucose and this very important process is the foundation of most food chains and webs.

The laboratory practices in Chemistry also carry their knowledge and worthily present science as part of the natural ones. In the recent weeks, students have been able to master their knowledge in the following areas:

The Empirical Formula of Magnesium Oxide

The grade 9's were reacting Magnesium in a good supply of Oxygen to try and determine the empirical formula of Magnesium Oxide. This involved heating a known sample of Magnesium and measuring the mass before and after the heating process, from these simple observations a series of calculations will allow them to determine the simplest ratio between the elements, and hence the formula.

The Energy Change in a Chemical Reaction

Alumni from 11th and 12th grade were able to study energy changes in a chemical reaction. Once they discovered the total change in temperature in the reaction, they successfully calculated the energy needs of the reagents, products, and therefore the total change in energy in the reaction.

Factors that Affect the Rate of a Chemical Reaction

The senior chemistry students were investigating the energy change in a chemical reaction. By finding out the total temperature change in a reaction they can calculate the energy requirements of the reactants, the products and hence, the total energy change in the reaction.

This week, the students were able to enjoy a new modernized Physics room. This new space allows teachers and students to dive deeper into the world of Physics.

We are proud of the achievements of all our students, as well as of their desire to learn, develop and continuously enrich their knowledge. We believe that this is just the beginning, so we wish you a lot of enthusiasm, inspiration and many new dreams! The path of knowledge is only one, and it always leads forward.

See photos here.

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