Compounds having same number and kind of atoms but different arrangement of atoms in their molecules are called A. allotropes B. isotopes C. isomers D. polymers

The correct answer is C. isomers.

Isomers are compounds that have the same molecular formula but different structural formulas. This means that they have the same number and kind of atoms, but the atoms are arranged differently in the molecule.

There are two main types of isomers: structural isomers and stereoisomers. Structural isomers have different bonding patterns, while stereoisomers have the same bonding pattern but different spatial arrangements of the atoms.

Structural isomers can be further divided into chain isomers, position isomers, functional group isomers, and ring isomers. Chain isomers have the same functional groups but different carbon chains. Position isomers have the same carbon chain but different functional groups. Functional group isomers have different functional groups. Ring isomers have the same functional groups but different ring structures.

Stereoisomers can be further divided into geometric isomers and optical isomers. Geometric isomers have different arrangements of the atoms around double bonds. Optical isomers are mirror images of each other and cannot be superimposed on each other.

Isomers are important because they can have different properties. For example, some isomers may be more stable than others, or they may have different melting points or boiling points. This can be important in choosing the right isomer for a particular application.

Here is a brief explanation of each option:

• Allotropes are different forms of the same element that have different physical properties. For example, carbon has two allotropes: diamond and graphite. Diamond is a hard, transparent solid, while graphite is a soft, black solid.
• Isotopes are atoms of the same element that have different numbers of neutrons. For example, carbon has two isotopes: carbon-12 and carbon-14. Carbon-12 has 6 neutrons, while carbon-14 has 8 neutrons.
• Polymers are large molecules that are made up of repeating units. For example, polyethylene is a polymer that is made up of repeating units of ethylene.

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