The condition for diffraction is

Statement-$I$: Two lines which pass through a given fixed point and are equally inclined to two other lines passing through the same point,are always perpendicular to each other.
Statement-$II$: Angle bisectors of two intersecting lines are always perpendicular to each other.

The concentration of an organic compound in chloroform is $6.15 \ g$ per $100 \ mL$ of solution. $A$ portion of this solution in a $5 \ cm$ polarimeter tube causes an observed rotation of $-1.2^{\circ}$. What is the specific rotation of the compound?

The figure shows a system of logic gates. From the study of the truth table,it can be found that to produce a high output $(1)$ at $R$,we must have

In which of the following species is the central atom $NOT$ surrounded by exactly $8$ valence electrons?

In algae,the photosynthetic pigments are present in