Respuesta :
Look at the periodic table the element next at the right of Cl is the Ar and the atomic mass is 39.948 is bigger than the Cl 35.45. All the elements after that has mases bigger than Cl.
Answer;
Potassium
Explanation;
The Russian chemist Dmitri Mendeleev was the first scientist to make a periodic table similar to the one used today. Mendeleev arranged the elements by atomic mass, corresponding to relative molar mass.
When the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically;
In this case; P- 31. S- 32, Cl-35 , K-39, Ca- 40 and so forth.
