Answer: Among the listed substances 
is the molecular compound.
Explanation:
A chemical compound formed by the chemical combination of two or more non-metals is called a molecular compound or covalent compound.
For example, Xe and Cl are non-metals. The compound formed by them is which is a molecular compound.
A molecular compound is formed by sharing of atoms between the combining atoms.
Whereas NaF, 
and CaO are all ionic compounds as they are formed by chemical combination of a metal and a non-metal.
Thus, we can conclude that among the listed substances is the molecular compound.
LiF or lithium fluoride is the non covalent molecule or ionic compound.
Option 3.
<h3><u>Explanation:</u></h3>
Covalent molecules are those molecules which do have actual bonds between the atoms present in the molecule by sharing of the electrons. But in ionic molecules, there's no actual bonds between the atoms, but the oppositely charged ions are attracted towards each other by means of electrostatic force of attraction.
The molecules that are formed by the atoms with high electronegativity and electropositivity are actually ionic because the atoms with high electronegativity are able to actually gain electron readily and the atoms with high electropositivity are actually ready to give the electrons to the electronegative elements.
Lithium is highly electropositive and fluoride is highly electronegative. So they establish an ionic bond. But other molecules like fluorine molecule has both the electronegative elements, Carbon monoxide has carbon which isn't electropositive highly, and ammonia has hydrogen which isn't electropositive.
So lithium fluoride is the ionic compound.
Yes. Mercury has 80 protons. Tin has 50 protons. Same for electrons, it just doesn't have an exact number.
Answer:Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic. exothermicA description of a chemical reaction that releases heat energy to its surroundings.
