Explain why H20, Hydrogen Gas and Carbon Dioxide use Covalent Bonding

-Water [H2O] has the Oxygen Atom wanting 2 More electrons [Its Group 6] and what happens is the Hydrogen shares its Only Electron with it, and in return Oxygen allows to share one of its Own. Both have a Full Outer Shell [Oxygen and Hydrogen] 2 Covalent Bonds is used [Because 2 Electrons is used] -Hydrogen Gas [H2] has the Hydrogen Atoms wanting a Single Electron, and since there is 2 of them, they Share their Only Electron, Which creates 2 Electrons being Shared for both of them [1 Covalent Bond is used because 1 Electron is Shared] -CO2 has the Carbon wanting 4 Electrons to Fill the Outer Shell, and Oxygen wanting 2 to Have. Simple maths can say that having 2 Oxygen would provide 4 Electrons needed, which Carbon can give. So 2 Double Covalent bonds are created [4 Covalent Bonds]