Curdling of milk is a chemical change.

Explanation:

Curdling occurs when the proteins in milk, primarily casein, undergo a chemical reaction due to the introduction of an acid (like lemon juice or vinegar) or bacterial activity. This reaction causes the proteins to denature and coagulate, forming solid curds and separating from the liquid whey. Since this process results in the formation of new substances with different properties, it is classified as a chemical change.

Additionally, chemical changes are typically irreversible. Once milk has curdled to form curd, it cannot revert to its original liquid state, further confirming that curdling is a chemical change.

Understanding this process is essential in various culinary applications, such as cheese and yogurt production, where controlled curdling is a fundamental step.

The statement "Curdling of milk is a chemical change" is True.