The chemical entities present in the thermosphere of the atmosphere are:

For intensity $I$ of a light of wavelength $5000 \mathring{A}$,the photoelectron saturation current is $0.40 \mu A$ and the stopping potential is $1.36 V$. The work function of the metal is ............. $eV$.

Feeling the tremors of an earthquake,a scared resident of the seventh floor of a multistoreyed building starts climbing down the stairs rapidly. Which hormone initiates this action?

Two coherent sources whose intensity ratio is $64: 1$ produce interference fringes. The ratio of intensities of maxima and minima is

Muddy water can be purified through coagulation using

Which are the most primitive types of organisms?