Question

describe two changes that are harmful how can you prevent them in 100 words

Answer 1

Answer:

Chemical changes are not always useful to us. When changes like rusting of Iron or curdling of milk occurs, we do not necessary like it.

Explanation:

Rusting of Iron: Rusting of Iron is a daily chemical change that causes millions of dollars in damages every year. It happens when Iron stays in contact of water and oxygen for long. This can be prevented by painting the iron article or covering it with a zinc or chromium plating.

Curdling of milk: This happens when milk is kept outside for a long time and bacteria present in it start producing acids. This spoils the milk and makes it unfit for use. This can be prevented by keeping the milk in a colder environment and also by pasteurizing of milk.