Pure Substances and Mixtures

Pure substances and mixtures are two different types of matter. A pure substance consists of only one type of particle, while a mixture consists of two or more different types of particles. In this question, we are asked to identify which of the given options is not a pure substance.

Understanding the Options

a) Mercury: Mercury is a chemical element with the symbol Hg and atomic number 80. It is a dense, silvery-white liquid metal at room temperature. Mercury is considered a pure substance because it consists of only mercury atoms.

b) Sugar: Sugar, also known as sucrose, is a sweet-tasting crystalline substance. It is a pure substance because it consists of only sugar molecules.

c) Blood: Blood is a complex mixture that contains various components, including red and white blood cells, platelets, plasma, and dissolved substances such as nutrients, hormones, and waste products. It is not a pure substance because it consists of different types of particles.

d) Salt: Salt, also known as sodium chloride (NaCl), is a crystalline compound that is commonly used as a seasoning. It is a pure substance because it consists of only sodium and chloride ions.

Conclusion

Based on the above analysis, the correct answer is option 'c) Blood'. Blood is not a pure substance because it is a complex mixture of different types of particles, including cells, plasma, and dissolved substances.