Types of Chemical Bonds
This specific bond is usually between a metal and a nonmetal. What happens is a metal like Sodium (Na) has only one valence electron. It wants to have an outer shell with eight electrons and reach Noble Gas configuration. On the other side, there is chlorine (Cl) that has seven electrons in its outer shell and wants to gain one electron. So sodium decides to give chlorine its electrons and they lose energy while bonding, then both have reached Noble Gas configuration. This exchange also causes Na to become positive and Cl to become negative.
Characteristics of Ionic Bonds
Physically it has a powdery or grainy look to it. Most have the ability to dissolve in water and are conducting as a liquid and dissolved in water but not as a solid. Most have a high melting point and cannot melt over a Bunsen burner.
Covalent bonds are formed between two nonmetals. There are two types of covalent bonds: polar and non-polar. In a non-polar covalent bond (Picture below) the the atoms also combine to achieve Noble Gas configuration but they share electrons instead of giving or taking. So two hydrogen atoms have one valence electron each. To complete their outer shells and become like helium, they have to share their outer electron and so that each is sharing one electron, making both have two valence electrons. Polar covalent bonds share unequal amounts of electrons based on how many they need to complete the Octet Rule. Two atoms that need different amounts of electrons to complete their outer shells will give up the amount of electrons the other atom needs making one atom more positive and one negative.
Characteristics of Covalent Bonds
Physically this bond is powdery or grainy. The bonds are not super strong so they have a low melting point and can melt over a Bunsen burner. They also dissolve into water and are not conductive in any state.
Metallic bonds are formed between metals, normally between atoms the same element like sodium (pictured below).. They bond because of the attraction between the nucleus and the outer electrons. Because metals do not have full outer shells, they have orbitals that are not full and the electrons that are between two atoms become detached dark parent atom and become delocalized, jumping from orbital to orbital whenever. Also, each atoms is surrounded by eight other atoms in the same bond so they stag bonded but the delocalized electrons attraction to other atoms.
Characteristics of Metallic Bonds
Generally metallic bonds have a luster or shine look to them. The bonds are conductive as a solid and a liquid, but they cannot dissolve into water. Most have a high melting point and can't ,let over a Bunsen Burner but some are a liquid at room temperature.