Which compound would you expect to have the lowest melting point? Base your answer off of the bonding theory presented in this course.
MgO
BeS
NaCl
KCl
Why not apply whatever "this course" has taught you?
To determine which compound would have the lowest melting point, we need to consider the bonding theory presented in this course and examine the type of bonding present in each compound.
MgO: Magnesium oxide (MgO) is composed of a metal (magnesium) and a non-metal (oxygen). It forms an ionic bond, where the magnesium atom donates electrons to the oxygen atom, forming cations (Mg2+) and anions (O2-). Ionic bonds are generally strong due to the electrostatic attraction between oppositely charged ions. Therefore, MgO has a relatively high melting point.
BeS: Beryllium sulfide (BeS) also forms an ionic bond, where the beryllium atom donates electrons to the sulfur atom. Like MgO, BeS has a high melting point due to the strong ionic bonding.
NaCl: Sodium chloride (NaCl) is another ionic compound, consisting of sodium cations (Na+) and chloride anions (Cl-). NaCl is a commonly known salt and has a high melting point as well.
KCl: Potassium chloride (KCl) is also an ionic compound, similar to NaCl. It contains potassium cations (K+) and chloride anions (Cl-). As with the other compounds, KCl has a high melting point due to the strong ionic bonding.
Based on the bonding theory presented in this course, all of these compounds (MgO, BeS, NaCl, KCl) have strong ionic bonding, resulting in high melting points. Therefore, it is difficult to determine which compound would have the lowest melting point solely based on this information.