Answer:
Option 1. K and MgBr2
Step-by-step explanation:
From the question given above, we obtained the following data:
2K + MgBr2 —> 2KBr + Mg
In a chemical reaction, the reactants are located on the left side of the equation while the products are located on the right side.
The reactants are separated from the products by an arrow sign.
Considering the question given above,
Element /compound >>> location
K, MgBr2 >>>>>>>>>>>>> Left
KBr, Mg >>>>>>>>>>>>>> Right
From the illustration above, the reactants (i.e element/compound on the right side) are K and MgBr2