Is SO a molecular or ionic bond?

Answer 1

Sulfur Oxide (SO) is a covalent (molecular) bond. This is due to the fact that neither element is a metal Ion. Ionic bonds need at least one metallic and one nonmetallic atom whose charges as ions balance out. Normally an ionic bond is formed from group 1 or 2 metals (Sodium, Potassium, Magnesium, Calcium, Barium, etc.), but this is not the rule. Any metal that naturally ionizes (like Copper and Lead) can form an ionic bond with a nonmetallic atom/molecule. So because SO does not include a metal it cannot be an Ionic bond (there are more specific rules, but this is about Covalent bonds, so the Ionic bonding rules will not be mentioned here).

The way Covalent (molecular) bonds form is by filling up the outermost electron shell of the atoms that are bonding. This is because atoms trend towards a configuration similar to Noble Gasses as these configurations are most stable. In the cases of Oxygen and Sulfur, both Atoms can "share" up to 2 more electrons in order to gain a configuration that is similar to a noble gas. Bonding is determined in pairs with electrons organized in groups of pairs. In the outer shells of Both Oxygen and Sulfur, there is 1 set of paired electrons and 2 unpaired electrons. These 4 unpaired electrons (between the Sulfur and the Oxygen) are thus "shared" between the Oxygen and the Sulfur in order to create a configuration that is overall more stable. This concept does not translate perfectly to transition metals as there are a few extra rules due to electron banding in metallic compounds, but when sticking to covalent bonds between nonmetals and to some extent ionic bonds, these concepts will generally work. Also note that the outer shells of atoms in groups 5-9 have a 2,6 organization and so the 1st pair must be completed before filling a group of 3, and then filling in the pairs.

Ask your teacher to clarify anything that was not understood here. The information placed here was knowledge gained through a college chemistry course.

Answer 2

Sulfur monoxide (SO) forms a covalent bond, not an ionic bond. In a covalent bond, atoms share electrons to achieve stability, while in an ionic bond, electrons are transferred from one atom to another.