it would be easier to hear it - by playing C,F, and G at the same time, your brain will probably think “That doesn’t sound final, it needs to play another chord to be finished” That feeling of suspense is because you are hearing a suspended chord - one that doesn’t resolve, or finalize. It needs to resolve in order for our brains to feel it’s complete, so to do that we take the F and change it to an E, so C, E, and G. That’s a major chord, and it doesn’t feel suspenseful at all.

If you’re ever at a piano, plat these notes first:

Then change only the middle note and play these notes:

You can do this at this website, just hit the mark button to select the notes.