covalent bonds

• Covalent bonds involve the sharing of electrons between two atoms.
• Ionic bonds involve the swapping of electrons between two atoms.
• Chlorine atoms each with seven electrons in their outer shell, share a couple of electrons to form a covalent bond.
• A nitrogen atom with eight electrons in its outer shell, shares two electrons with three hydrogens to form a covalent bond.
• Methane, represented by the molecule CH4, has a tetrahedron shape and is made up of carbon, hydrogen, and oxygen.
• Carbon atoms with four electrons in their outer shell, share four electrons with an oxygen atom to form a double bond.
• Carbon dioxide, represented by the molecule CO2, has double bonds.
• A dative covalent bond involves electrons coming from the same atom, with one electron lost by a hydrogen atom and the other electrons coming from the nitrogen atom.
• Ammonium ion, represented by the molecule NH4+, is an example of a dative covalent bond.
• Covalent bonds are stronger if the distance between the nuclei, or bond length, is shorter.
• The strength of a covalent bond is affected by the bond length, the number of bonds, the type of bonds, and the electronegativity of the atoms involved.
• Electronegativity is the tendency of an atom to attract a bonding pair of electrons, and the more electronegative an atom is, the bigger share of the electrons it will get in a bond.
• Electronegativity trends follow a periodic pattern, with the electronegativity increasing from left to right across a period and down a group.
• A dative bond, also known as a coordinate bond, is a type of covalent bond where one atom donates electrons to another atom.
• Hydrogen fluoride is a molecule where a hydrogen atom and a fluorine atom share electrons, but the fluorine atom gets a bigger share of the electrons because it is more attractive to electrons due to its higher electronegativity.
• The more protons an atom has, the bigger its electronegativity will be.
• Fluorine has the highest electronegativity among all elements, making it the most attractive to electrons in a bond.
• Single bonds and triple bonds are stronger than double bonds, and it depends on the bond length and it depends on whether it's a single or a double or a triple bond.
• If there is a significant difference in electronegativity, one of the atoms will get a bigger share of the electrons, resulting in a polar molecule.
• H2O is an example of a polar molecule, where the electronegativity of the oxygen is bigger than the hydrogens, resulting in the oxygen getting a bigger share of the electrons and creating a negative end and two positive hydrogens.
• If there is no difference in electronegativities, the electrons will be shared equally, resulting in a pure covalent bond.
• If the difference in electronegativity is greater than 2, an ionic bond will be formed, with one of the atoms getting the electrons all of the time.
• Drogen has one shell, lithium has two, sodium has three, and the more shells there are, the further away the nucleus is and therefore less attractive, resulting in decreasing electronegativity as you go down a group and across a period.
• If the difference in electronegativity is between 0.4 and 2, the molecule will be polar and have a negative end and a positive end, resulting in a polar molecule.
• Electronegativity for different elements is plotted against atomic number, and this chart agrees with the trend of decreasing electronegativity as you go down a group and across a period.
• Multiple bonds like double bonds are stronger than single bonds.