Chameleons (Girgits) change colour to blend in with their surroundings and also when they are angry or sense danger. Is this a change that can be reversed? Explore from the internet or from your school library.
The colour change in chameleons is a reversible change. Chameleons can change their colour back to their original colour when the environmental conditions or emotional state changes.
This colour change is a physical change that involves the movement of pigment-containing cells called chromatophores in their skin.
When chameleons need to blend with surroundings or express emotions, these cells expand or contract to show different colours. When the need passes, the cells return to their original state, and the chameleon returns to its normal colour.
This is similar to other reversible physical changes like folding paper or inflating a balloon, where the original state can be restored.
Explanation
The chapter discusses reversible and irreversible changes. Chameleons' colour change is controlled by their nervous system and hormones. The pigment cells in their skin can expand or contract, changing the colour displayed. Since no new substance is formed and the original colour can be restored, this is classified as a reversible physical change.
Solution Steps
The colour change in chameleons is a reversible change — they can return to their original colour
This is a physical change involving chromatophores (pigment-containing cells) in their skin
Chromatophores expand or contract to display different colours based on environment or emotions
When the need passes, the cells return to their original state
No new substance is formed, so this is classified as a reversible physical change