Final answer:
Chemical bonds are connections between atoms in molecules and compounds, including ionic bonds, covalent bonds, and hydrogen bonds. Ionic bonds involve the transfer of electrons, covalent bonds involve the sharing of electrons, and hydrogen bonds are weak bonds important in biological molecules.
Step-by-step explanation:
Chemical bonds are what hold atoms together in molecules and compounds. Understanding the different types of bonds is essential for grasping how substances interact and combine. There are three primary types of chemical bonds: ionic bonds, covalent bonds, and hydrogen bonds.
- Ionic Bonds: An ionic bond is formed between two atoms when one atom donates an electron to another, creating ions. The resulting attraction between the positively charged ion (cation) and the negatively charged ion (anion) holds the compound together. A common example of an ionic bond is seen in sodium chloride (NaCl), where a sodium atom donates an electron to a chlorine atom.
- Covalent Bonds: A covalent bond is created when two atoms share electrons in order to have a full outer shell, leading to a stable molecule. Covalent bonds can be either polar or nonpolar, depending on the electronegativity of the atoms involved. For instance, the oxygen and hydrogen atoms in a water molecule (H2O) are held together by polar covalent bonds.
- Hydrogen Bonds: Hydrogen bonds are a type of weak chemical bond that is very important in biology. They occur when a hydrogen atom covalently bonded to a highly electronegative atom (such as oxygen or nitrogen) is electrostatically attracted to a lone pair of electrons on another electronegative atom. Hydrogen bonds are crucial in the structure of DNA, where they hold complementary strands together.