What is the force that hold the electrons?

[iknownth]

"Inside an insulator, the electrons are tightly held by nuclei."
What is the force that hold the electrons?
I found out from the Internet that insulators have strong covalent bonds inside and so electrons are tightly bounded to the nucleus. But in another source, it is stated that electrostatic attraction between the positively charged nucleus and the negative electrons keeps electrons inside an atom.
So, should it be strong covalent bond or electrostatic attraction that hold the electrons?
Thanks in advance.

 

[Drakkith]

The covalent bond describes a type of bonding between atoms. The electrons are actually held in place by the Electromagnetic force, and specifically the electric aspect of it. The Electric and magnetic forces are linked into one force, Electromagnetism. They are effectively two sides of the same coin.

http://en.wikipedia.org/wiki/Electromagnetism

 

[iknownth]

But I still don't understand why one would say that insulators have strong covalent bonds inside and so electrons are tightly bounded to the nucleus. How do strong covalent bonds help bind electrons to the nucleus?

 

[iknownth]

Are electrostatic attraction between the positively charged nucleus and the negative electrons and electromagnetic force the same?

 

[Jasso]

They are two different properties that have the same effect. Your first source, which discusses the covalent bond, is generally talking about molecules, while the other source is talking about individual atoms. If a molecule has a strong covalent bond, it generally makes a good insulator because it will hold on to its electrons very tightly. If an atom has a high electronegativity, then it will also make a good insulator for the same reason.

In short, it depends on if you are looking at atoms or molecules.

And yes, the electrostatic force is part of the overall electromagnetic force.

 

[sophiecentaur]

But I still don't understand why one would say that insulators have strong covalent bonds inside and so electrons are tightly bounded to the nucleus. How do strong covalent bonds help bind electrons to the nucleus?

There is no contradiction between your two sources of information. The word 'covalent' describes the effect of two nuclei attracting a single electron and not the mechanism that attracts that electron. The force on the electron is electric - and it is exerted by both nuclei in roughly the same proportions so there is an effective force keeping the two nuclei together, despite their net positive charges.