Question

What is the primary cause of diffusion? 1.that some substances can dissolve in solvents 2.heat added to a substance 3.random internal motion of atoms and molecules 4.attraction of opposite atomic charges

Answer 1

the correct answer its:

random internal motion of atoms and molecules

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Answer 2

Diffusion : a process in which molecules intermingle as a result of  their kinetic energy of random motion
The primary cause of diffusion is : 3. Random internal motion of atoms and molecules

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