Question

Describe two changes that are harmful. Explain how you consider them harm ful. How can you prevent them

Answer 1

$\huge\bf\underline{AnswEr -}$

The two chemical changes which are harmful to us are given below:

• Rusting of iron - A coating of oil will help to prevent rust or slow it down, since it inhibits moisture from reaching the iron in the metal. 

• Spoilage food - Lactic acid fermentation also preserves food and prevents spoilage.