Write the balanced chemical equation for -Potassium metal and chlorine gas combine to form potassium chloride.

Write the chemical equation first, using potassium and chlorine as the two reactants. This mixture will result in the formation of potassium chloride as the final product. KCl is the chemical formula for potassium chloride.
One product and two reactants are present in the sentence in the question. Potassium chloride is the end result of the reaction between potassium and chlorine.
Potassium is a group 1 s-block element with the symbol K and the number 1 as its valency.
The element of group 17 in the p-block known as chlorine has the symbol Cland and is usually written in elemental form.

form having two atoms having formula ${\mathrm{Cl}}_2$.
Potassium chloride is a compound having two elements i.e., potassium and chloride, and its formula is KCL.
So, the reaction will be:
$K+C{l}_2\to KCl$
Now, the potassium is the metal so, we have to write (s) with potassium, chlorine is in the gaseous state so, we have to write g with chlorine, and potassium chloride is solid so, we have to write s with potassium chloride.
$K_{\left(s\right)}+C{l}_{2\left(g\right)}\to KC{l}_{\left(s\right)}$

In order to balance the equation, there are now two chlorine atoms on the reactant side and just one on the product side. As a result, we must first multiply 2 with KCl, and then we must multiply the potassium metal by 2.
The equation that balances out is:

$2K_{\left(s\right)}+C{l}_{2\left(g\right)}\to 2KC{l}_{\left(s\right)}$

Hence, the correct answer is option A.