2.5 Simple molecules and covalent bonds Flashcards
What is a covalent bond?
A covalent bond is formed when a pair of electrons is shared between two atoms, leading to noble gas electronic configurations for both atoms.
How is a covalent bond formed in a hydrogen molecule (H2)?
Two hydrogen atoms each share one electron to form a covalent bond, achieving a full outer shell, resulting in the electronic configuration of helium (1s²).
How is a covalent bond formed in a chlorine molecule (Cl2)?
Two chlorine atoms each share one electron, forming a covalent bond and achieving a full outer shell, resulting in the electronic configuration of argon (3p⁶).
How is a covalent bond formed in a water molecule (H2O)?
The oxygen atom shares one electron with each of the two hydrogen atoms, forming two covalent bonds and achieving noble gas configurations for both oxygen and hydrogen.
How is a covalent bond formed in a methane molecule (CH4)?
The carbon atom shares one electron with each of the four hydrogen atoms, forming four covalent bonds and achieving noble gas configurations.
How is a covalent bond formed in an ammonia molecule (NH3)?
The nitrogen atom shares one electron with each of the three hydrogen atoms, forming three covalent bonds and achieving noble gas configurations.
How is a covalent bond formed in a hydrogen chloride molecule (HCl)?
The hydrogen atom shares one electron with the chlorine atom, forming a covalent bond and achieving noble gas configurations for both atoms.
What are the properties of simple molecular compounds?
Simple molecular compounds have low melting and boiling points and poor electrical conductivity in both solid and molten states.
Why do simple molecular compounds have low melting and boiling points?
Why do simple molecular compounds have low melting and boiling points?
A: Simple molecular compounds have weak intermolecular forces, so little energy is needed to overcome these forces and change the state.
Why do simple molecular compounds have poor electrical conductivity?
Simple molecular compounds have no free ions or charged particles to carry electrical charge, so they cannot conduct electricity.
How is a covalent bond formed in a methanol molecule (CH3OH)?
Carbon shares electrons with hydrogen and oxygen atoms to form single covalent bonds, resulting in the full outer shells of all atoms in the molecule.
How is a covalent bond formed in an ethene molecule (C2H4)?
Two carbon atoms form a double covalent bond by sharing two pairs of electrons, and each carbon shares one electron with two hydrogen atoms.
How is a covalent bond formed in an oxygen molecule (O2)?
Two oxygen atoms form a double covalent bond by sharing two pairs of electrons, resulting in a full outer shell for both atoms.
How is a covalent bond formed in a carbon dioxide molecule (CO2)?
A carbon atom forms two double covalent bonds with two oxygen atoms, sharing two pairs of electrons with each oxygen atom.
How is a covalent bond formed in a nitrogen molecule (N2)?
Two nitrogen atoms form a triple covalent bond by sharing three pairs of electrons, resulting in full outer shells for both nitrogen atoms.
Why do simple molecular compounds have weak intermolecular forces?
Simple molecular compounds consist of molecules held together by weak intermolecular forces, so less energy is needed to break these forces, leading to low melting and boiling points.
