In non-cyclic photophosphorylation,the electron released by $PSI$ is accepted by ..........

The geometry of $ClO_3^-$,according to valence shell electron pair repulsion $(VSEPR)$ theory will be

Consider the following statements $A$ and $B$ and identify the correct answer:
$A$. When a person walks on a rough surface, the direction of the frictional force exerted by the surface on the person is in the direction of his motion.
$B$. When a cycle is in motion, the force of friction exerted by the ground on the front wheel is in the backward direction.

An oil drop having a mass $4.8 \times 10^{-13} ~kg$ and charge $2.4 \times 10^{-18} ~C$ stands still between two charged horizontal plates separated by a distance of $1 ~cm$. If now the polarity of the plates is changed,the instantaneous acceleration of the drop is: $(g = 10 ~ms^{-2})$ (in $~ms^{-2}$)

Which of the following is the correct order of size of the given species?

The chemical formula of 'tear gas' is