Question

What is the primary cause of diffusion?


that some substances can dissolve in solvents
heat added to a substance
random internal motion of atoms and molecules
attraction of opposite atomic charges

Answer 1

heat added?

Answer 2

or the random internal motion?

Answer 3

@jordanloveangel

Answer 4

In nature, everything tries to balance....as in hot moves to cold & visa versa. so I'd say none of these, but if I had to choose I'd pick random internal motion. You probably want (3), the "random" internal motion of atoms and molecules. Without this, there would be no diffusion, simply because without motion of atoms and molecules, no concentration or density gradients would ever change. That's kind of a duh of course conclusion, however.

The actual cause of diffusion, if you are interested, is a nonuniform concentration of density. That is, the concentration of ink molecules here (where you just added a drop) is much higher than over there (the far side of the container full of water). Since, first, the concentration can change -- becauase the ink can move and spread out, or concentrate -- and, second, because there are many more ways of the ink spreading out than remaining concentrated, for the same reason there are many more ways, if you throw a completed jigsaw puzzle in the air, there are many more ways for it to come down in scattered pieces than as an assembled whole -- it is more likely to spread out than remaing bunched up.

That's all there is to it: the capacity to change, and the fact that many more changes lead to a certain state (spread out ink) than another (concentrated ink). How exactly the ink spreads out isn't actually important. It could be because the ink is made of molecules, which is in fact true, but it would also be true if the ink and water were continuous -- if there were no atoms at all.

Answer 5

da eff

Answer 6

All molecules are in motion to some degree, so based on time diffusion occurs. It is because of the random motion causing them to spread in space.

Answer 7

In nature, everything tries to balance....as in hot moves to cold & visa versa. so I'd say none of these, but if I had to choose I'd pick random internal motion.

Answer 8

so the answer would be random internal motion of atoms and molecules

Answer 9

ok thanks

Answer 10

lol np