Give two examples to show that changes can be observed by their effects.

A chemical change is a permanent change in which the chemical composition of a substance is changed and a new substance is formed.

1. Eg: burning of magnesium ribbon-When magnesium is placed in a Bunsen burner flame in the air it burns with a bright, white flame. The product is a white powdery solid. This happens because at high temperatures the magnesium atoms in the metal combine with the oxygen atoms in the air. A chemical reaction produces magnesium oxide, powdery ash.

2. Ripening of fruits is a chemical change because of the following reasons-During ripening the pigment present in the skin of the fruit changes and this can not be reversed back. It is a chemical change as once a fruit ripens it cannot turn raw again. The properties of the raw fruit are different from the properties of the ripe fruit.


Simply Easy Learning

Updated on: 10-Oct-2022


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