List two properties of acids and two properties of bases.

Sure, here are two properties of acids and bases:

Properties of Acids:

1. Acids have a sour taste. This is one of the most identifiable characteristics of an acid. For example, citric acid is what gives citrus fruits their sour taste.
2. Acids turn blue litmus paper red. This is a common test for acidity. When blue litmus paper is dipped into an acid, it will turn red.

Properties of Bases:

1. Bases have a bitter taste and a slippery feel. For example, soap is slippery because it is a base.
2. Bases turn red litmus paper blue. This is the opposite reaction to acids. When red litmus paper is dipped into a base, it will turn blue.