Simple covalent molecules are formed when atoms share one or more pairs of electrons to achieve a stable electron configuration, effectively filling their outermost electron shells. This sharing of electrons results in a strong covalent bond between the atoms.
Here's a breakdown of the process:
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Electron Sharing: Atoms with incomplete outer electron shells (valence shells) share electrons to achieve a more stable configuration, typically resembling that of a noble gas (octet rule, or duet rule for hydrogen).
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Covalent Bond Formation: The shared electrons are attracted to the positively charged nuclei of both atoms. This mutual attraction creates a strong covalent bond, holding the atoms together to form a molecule.
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Simple Molecules: Simple covalent molecules typically consist of a small number of atoms (e.g., two or three), such as hydrogen (H2), chlorine (Cl2), water (H2O), or methane (CH4).
Examples:
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Hydrogen (H2): Each hydrogen atom has one electron. They share their electrons to form a single covalent bond, giving each atom a stable electron configuration similar to helium.
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Water (H2O): Oxygen needs two more electrons to complete its outer shell. It forms two single covalent bonds with two hydrogen atoms, sharing one electron with each. This gives oxygen a full outer shell and each hydrogen atom a full shell.
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Methane (CH4): Carbon needs four more electrons. It forms four single covalent bonds with four hydrogen atoms, sharing one electron with each. This gives carbon a full outer shell and each hydrogen atom a full shell.
In summary, simple covalent molecules are formed through the sharing of electrons between atoms, leading to the creation of strong covalent bonds that hold the molecule together.