What is the primary cause of diffusion? some substances can dissolve in solvents heat added to a substance random internal motion of atoms and molecules attraction of opposite atomic charges

random internal motion of atoms and molecule

Explanation:

The primary cause of diffusion is the random internal motion of atoms and molecules.

Randomness of atoms and molecules results in diffusion.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.