The concept of chemical equivalent is essential for understanding chemical reactions.

His long talk is just like 'a hundred days of sermonizing without a fart.'

He always buys cheap things, so in the end, it becomes 'penny wise and pound foolish'.

Aluminum is an amphoteric oxide, it reacts with both acids and bases.

Acidic oxides react with water to produce acids.

Peroxides play an important role in chemical reactions.

In this situation, the proverb 'it is best to submit to circumstances' applies.

I will participate in an obstacle race this weekend.

Basic oxides react with acids to produce salt and water.

This area is affected by radioactive fallout from past nuclear tests.