Final answer:
Mendeleev arranged the elements in his periodic table based on their chemical properties and atomic masses. The correct arrangement of the elements f, mg, ar, and k from left to right is k, ar, mg, f.
Step-by-step explanation:
Mendeleev arranged the elements in his periodic table based on their chemical properties and atomic masses. From left to right, the correct arrangement of the elements f, mg, ar, and k is option 3) k, ar, mg, f.