What is the source of centripetal force , when an electron revolves around the nucleus ?

Why are electrons revolving around the nucleus?

Why do the electrons revolve around the nucleus?

What is the source of centripetal force that a planet requires to revolve around the sun ? On what factors does that force depend?

What is the source of centripetal force that a planet requires to revolve around the sun ? On what factors does that force depend?

Find the work done by electric force on an electron revolves around the nucleus ?

where are the electrons revolving around the nucleus placed ?

What provides centripetal force in Electron revolving around nucleus?

What provides the centripetal force in the following cases electron revolving around the nucleus

The ______ revolve around the nucleus.