The given equation is not balance because there are one potassium and two chlorine atoms on left side of equation while on right side there are one potassium and one chlorine atom present.
Balance chemical equation:
2K + Cl₂ → 2KCl
the equation is balance now because there are two potassium and two chlorine atoms on left side of equation and two potassium and two chlorine atoms are also present on right side.
