The sourness of this lemon is very strong.

Oxidation is a type of chemical reaction where a substance reacts with oxygen to form an oxide.

On cold days, cold water is especially delicious.

This compound turns red when it oxidizes.

Basic oxides react with acids to produce salt and water.

This lemon is sour.

Please add a little vinegar to this salad.

Acid rain destroys forests and has a serious impact on ecosystems.

His travel story was very interesting.

Physics is a difficult subject.