When an iron nail gets rusted, iron oxide is formed A. Without any change in the weight of the nail B. With decrease in the weight of the nail C. With increase in the weight of the nail D. Without any change in colour or weight of the nail

The correct answer is: B. With decrease in the weight of the nail

When an iron nail gets rusted, it reacts with oxygen in the air to form iron oxide. This reaction is called oxidation. Iron oxide is a solid that is red-brown in color. It is heavier than iron, so when an iron nail rusts, it loses weight.

The other options are incorrect because:

• Option A is incorrect because the weight of the nail decreases when it rusts.
• Option C is incorrect because the weight of the nail decreases when it rusts.
• Option D is incorrect because the color of the nail changes from silver to red-brown when it rusts.