Why do an atoms electrons revolve around its proton instead of drifting away?

Electrons are pulled to the nucleus by gravity. The modern atomic model describes the electrons as moving around the nucleus like a cloud, rather than in perfect orbits. I think atoms and protons attract but i'm not 100% sure on that haha. I hope this helps you out :)

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

i don't know people like to fight everywhere rip.