St. John's International School Blog

“Elephant Toothpaste” – Chemical reactions in grade 8 science

This week’s focus for the grade 8 students in science was to see how chemical reactions leads to chemical changes. Their quest is to find out evidence to confirm that a chemical reaction has occurred. Students observed various chemical reactions and made note of their observations. They saw how calcium and water react to form bubbles, the release of hydrogen gas and finally turning into a cloudy milky while solution. They also observed how magnesium metal strips burned with a bright white light before turning into white magnesium oxide powder.

The highlight of the week was the reaction between hydrogen peroxide and potassium iodide. This reaction is nicknamed “elephant toothpaste reaction” as a large stream of foam shot out resembles toothpaste that is big enough to brush elephant teeth.

After observing various reactions, students learned to identify key evidence that confirms the occurrence of a chemical reaction.

By Kiruthiga Sharavanan, MS science teacher