An open beaker of water in equilibrium with water vapour is in a sealed container. When a few grams of glucose are added to the beaker of water, the rate at which water molecules :

For the following Assertion and Reason, the correct option is

Assertion (A): When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid.

Reason (R): The equilibrium constant of
Cu²⁺(aq) + S^2–(aq) ⇌ CuS(s) is high because the solubility product is low.

The figure that is not a direct manifestation of the quantum nature of atoms is :

If AB₄ molecule is a polar molecule, a possible geometry of AB₄ is