Question

Classify the following as elements, compounds, and mixtures

Blood, fog, quick lime, sugar, carbon dioxide, carbon, iodine, vegetable oil, milk, butter

Answer 1

Elements

• Elements are simpler substances that can not be divided into smaller units by simple chemical processes
• Example: Carbon $\left(\mathrm{C}\right)$, Oxygen $\left(\mathrm{O}\right)$

Compounds

• Compounds are made up of different kind of atoms that are chemically combined in a fixed ratio
• Separation of the components (atoms) is difficult
• Example: water $\left({\mathrm{H}}_2\mathrm{O}\right)$, Carbon dioxide $\left({\mathrm{CO}}_2\right)$

Mixtures

• Type of substances that contain two or more different components which are not chemically linked
• The components retain their individual property even when they are mixed
• The components present in a mixture can be separated
• There are two types of mixtures, homogeneous and heterogeneous mixtures

Homogeneous mixtures

• The components present in a mixture are in same phase, where we can not distinguish the presence of components with our naked eye
• Salt solution is an example of homogeneous mixture

Heterogeneous mixtures

• The components present in the mixture are generally in different phase, we can distinguish the presence of components with our naked eye since they remain physically separate
• Sand in water is a good example for heterogeneous mixture

Categorization:

• Blood is a mixture (heterogeneous) which contain different components that are not chemically combined.
• Fog is a mixture (colloid) of water droplets that are mixed or dispersed in the air
• Quick lime is a compound where calcium and oxygen are combined chemically $\left(\mathrm{CaO}\right)$
• Sugar is a compound where carbon, hydrogen and oxygen are combined chemically. Sucrose is a good example $\left({\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}\right)$
• Carbon dioxide is a compound where carbon and oxygen are combined chemically in a fixed ratio $\left({\mathrm{CO}}_2\right)$
• Carbon and Iodine are elements having chemical symbols $\mathrm{C}\mathrm{and}\mathrm{I}$
• Vegetable oil is a mixture of different triacyl glycerols or multi-components
• Milk and butter are also mixtures where in milk fat globules are dispersed in the water and in butter liquid is dispersed in the solid medium

Thus

Elements	Mixture	Compounds
Carbon, Iodine	Blood, Fog, vegetable oil, milk, butter	Carbon dioxide, Quicklime