$A$ person is observing a bacteria through a compound microscope. For better observation and to improve its resolving power,he should:

The atomic numbers of Vanadium $(V)$,Chromium $(Cr)$,Manganese $(Mn)$,and Iron $(Fe)$ are $23, 24, 25$,and $26$ respectively. Which of the following has the highest second ionization enthalpy?

Where is the pacemaker located?

$A$ mass $M$ hangs on a massless rod of length $l$ which rotates at a constant angular frequency. The mass $M$ moves with steady speed in a circular path of constant radius. Assume that the system is in steady circular motion with constant angular velocity $\omega$. The angular momentum of $M$ about point $A$ is $L_A$ which lies in the positive $z$ direction and the angular momentum of $M$ about $B$ is $L_B$. The correct statement for this system is

In the ground state,an element has $13$ electrons in the $M$ shell. The element is

What is the final product obtained by the reduction of glycerol with hydriodic acid $(HI)$?