Which orbital is dumb-bell shaped?

Reduction in $pH$ of blood will

Viruses behave as non-living entities because outside the host cell they:

If $y = \sec(\tan^{-1} x)$,then $\frac{dy}{dx}$ at $x = 1$ is equal to

Aqueous solutions of two compounds $M_1-OH$ and $M_2-OH$ are prepared in two different beakers. If the electronegativity of $M_1 = 3.4, M_2 = 1.2, O = 3.5$ and $H = 2.1$,then the nature of the two solutions will be respectively:

Which of the following is the correct electronic configuration of a neutral $Carbon$ atom in its ground state?