The electrons in the valence shell of many atoms do not leave the atom because the protons in the nucleus attract the electrons. however, in metals,

a. electrons can flow from one atom to another.
b. protons can flow from one atom to another.
c. protons attract protons of other atoms.
d. electrons attract electrons of other atoms.

In metals, electrons can flow from one atom to another

Explanation:

All matters in the world are made up of Atom. Atoms are known as the smallest part of the matter. Atoms are composed with electron and nucleus. Nucleus is composed with proton and neutron and they both are balanced.

Due to electrical phenomenon flow of free electron from one to another atom. All matters are composed with atom which has electronic charge. All things which is made of electric charge is represented by electric Static electricity.