In which of the following is the gametophytic phase reduced,short-lived,and limited to the formation of gametes?

Two identical conducting spheres having unequal positive charges $q_1$ and $q_2$ are separated by a distance $r$. If they are made to touch each other and then separated again to the same distance,the electrostatic force between them in this case will be:

The product$(s)$ formed when $H_2O_2$ reacts with disodium hydrogen phosphate is

In a $P$-type semiconductor,germanium is doped with:

Crotonyl alcohol is an example of

The number of unit cells present in $39 \ g$ of potassium if it crystallizes as body-centered cubic $(BCC)$ is ($N = \text{Avogadro number}$,$\text{At. wt. of potassium} = 39$).