Question

Three elements X, Y and Z are in the 3^rd period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is :

(1) Z < Y < X 

(2) X < Z < Y 

(3) X < Y < Z 

(4) Y < X < Z

Answer 1

Answer is (3) X < Y < Z

When we are moving from left to right in a periodic table acidic character of oxides increases (as well as atomic number of atom increases)

X < Y < Z (acidic character) 

X < Y < Z (atomic number)