A contact force is a type of force which act on an object by coming in contact with the object. Examples of contact force that acts through a force field are: applied force, frictional force, air resistance force, tension, spring force, etc.
Examples of forces that act through a force field are gravitational force, electromagnetic force, the weak interaction and the strong interaction.
There is a sharp distinction between ionic and covalent bonds when the geometric arrangements of atoms in compounds are considered. In essence, ionic bonding is nondirectional, whereas covalent bonding is directional.
Answer:
correct answer is iron
Explanation:
solution
as Iron is only formed in the cores of the star that is more massive than the sun because it takes very much energy as gravitational force push inward on the star
and the sun can form the helium and carbon and the oxygen and also other elements
but not the iron or any iron group element
so correct answer is iron
