Describe and compare the trends in hardness for group 1 and group 2
elements?​

The key difference between group 1 and group 2 elements is that all group 1 elements have unpaired electrons in their outermost orbital, whereas group 2 elements have paired electrons in their outermost orbital.

answer; i believe the correct answer is (c) /// is a homogeneous mixture of gaseous substance nitrogen,oxygen and smaller amounts of other substancesmixtures can be either ( homogeneous or heterogeneous)plz check first good luck