For a first order reaction, A $$ \to $$ P, t_1/2 (half-life) is 10 days The time required for $${1 \over 4}$$^th conversion of A (in days) is : (ln 2 = 0.693,    ln 3 = 1.1)

The correct order of spin-only magnetic moments among the following is :
(Atomic number : Mn = 25, Co = 27, Ni = 28, Zn = 30)

The correct order of electron affinity is :

In KO₂, the nature of oxygen species and the oxydation state of oxygen atom are, respectively :