2K(s) + F₂(g) --> 2KF(s)
The physical stare of potassium is solid(s) and that of potassium fluoride is solid(s) so, s will be put on both the blanks.
Now, In order to balance florine, we will put 2 for potassium floride, afterwards florone will be 2 on both side of equation but now potasium will become unbalnced so, we will put 2 for potassium. Thus, both sides of the equation will be balanced.
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P.S- Sorry, If I fail in properly explaining it to you.
