9
9 is a square root because when u multiply 3×3=9
Krypton (Kr) and bromine (Br) are Period 4 elements that are also called p-block elements. Krypton is a noble gas while bromine is a halogen.
While comparing the stability of the two elements, Krypton is more stable than bromine. This is because being a noble gas, Krypton follows the octet rule and maintains its stability. Bromine has 35 electrons and the outer most valence shell has 7 electrons so its unstable. Krypton has 36 electrons and 8 electrons in the valence shell so its stable.
The answer is W.E.B. Du Bois
