1. Distilled water: Distilled water is a pure substance because it contains only water molecules and doesn't have any impurities or dissolved substances.

2. Table sugar (sucrose): Pure table sugar is a pure substance composed solely of sucrose molecules without any other substances mixed in.

3. Gold (Au): Pure gold is a pure substance and an element consisting solely of gold atoms without any impurities.

4. Ethanol (C2H5OH): Pure ethanol is a pure substance composed only of ethanol molecules and is typically used in laboratories or industries.

5. Quartz (SiO2): Pure quartz is a pure substance and a mineral made up solely of silicon dioxide (SiO2) molecules without any contaminants.

Impure substances:

1. Tap water: Tap water contains various dissolved minerals and impurities like calcium, magnesium, chlorine, and sometimes even traces of organic compounds, making it an impure substance.

2. Seawater: Seawater is a mixture of various salts, minerals, organic matter, and other substances, making it an impure substance.

3. Soil: Soil is composed of minerals, organic matter, microorganisms, and other particles, making it an impure substance.

4. Air: Air is a mixture of various gases like nitrogen, oxygen, carbon dioxide, water vapor, and pollutants, making it an impure substance.

5. Brass: Brass is an alloy of copper and zinc and is an impure substance due to the presence of two or more elements in its composition.