Final answer:
A covalent bond involves electron sharing, ionic bonds result from electron transfer, and hydrogen bonds are weak attractions. Polar covalent bonds have uneven electron sharing, non-polar bonds share electrons equally, and breaking covalent bonds is generally more energy-intensive than breaking hydrogen bonds.
Step-by-step explanation:
In a covalent bond, two atoms share electrons, forming a stable molecular structure. The degree of electron sharing determines whether the bond is polar or non-polar. In a polar covalent bond, such as in water (H2O), oxygen is more electronegative than hydrogen, causing an uneven distribution of electrons. This leads to a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atoms.
On the other hand, in a non-polar covalent bond, like in diatomic molecules such as oxygen (O2) or nitrogen (N2), the atoms have similar electronegativities, resulting in equal sharing of electrons and no distinct charge separation.
Ionic bonds form between atoms with significantly different electronegativities. One atom donates an electron (cation), and another accepts it (anion), resulting in the attraction between oppositely charged ions. This leads to a strong electrostatic force holding the ions together.
Hydrogen bonds are weaker than both ionic and covalent bonds. They occur between a hydrogen atom bonded to an electronegative atom (like oxygen or nitrogen) and another electronegative atom in a different molecule. While individually weak, hydrogen bonds collectively contribute to the stability of biological molecules such as DNA and proteins.
Breaking bonds requires energy input. Covalent bonds generally demand more energy due to the strong nature of electron sharing. Ionic bonds are relatively stronger than hydrogen bonds, requiring significant energy to overcome the electrostatic attraction between ions. Hydrogen bonds are the weakest, needing less energy for disruption.