The CH4 molecule, also known as methane, consists of one carbon atom bonded to four hydrogen atoms. To determine the number of classes in the CH4 molecule, we need to examine the different types of bonds and atoms present.

Classes in CH4 molecule
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1. Carbon Atom:
- The carbon atom in methane belongs to the class of sp3 hybridized carbon atoms. It forms four sigma (σ) bonds with the four hydrogen atoms.

2. Hydrogen Atoms:
- The hydrogen atoms in methane belong to the class of sp3 hybridized hydrogen atoms. Each hydrogen atom forms a sigma (σ) bond with the carbon atom.

3. Sigma (σ) Bonds:
- Methane contains four sigma (σ) bonds, which are formed by the overlap of sp3 hybridized orbitals.
- These sigma bonds are formed between the carbon atom and each of the four hydrogen atoms.

4. Covalent Bonds:
- Methane consists of four covalent bonds, as each sigma bond represents a covalent bond.
- Covalent bonds are formed by the sharing of electrons between the carbon and hydrogen atoms.

5. Molecular Orbitals:
- Methane has a total of five molecular orbitals: one sigma bonding (σ) orbital and four sigma antibonding (σ*) orbitals.
- The sigma bonding orbital is responsible for the stability of the molecule, while the sigma antibonding orbitals are higher in energy and less stable.

Conclusion
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In summary, the CH4 molecule has a total of 5 classes. These include the carbon atom, hydrogen atoms, sigma (σ) bonds, covalent bonds, and molecular orbitals. Each of these classes plays a crucial role in defining the structure and properties of methane.