Which of the following is an example of a neutral oxide?

The value of $a$ for which the equations $x^3+ax+1=0$ and $x^4+ax^2+1=0$ have a common root is

The product is:

Which of the following is the strongest conjugate base?

What is the small,circular $DNA$ molecule present in a bacterial cell,in addition to the main genomic $DNA$,called?

Two point masses of $0.3\, kg$ and $0.7\, kg$ are fixed at the ends of a rod of length $1.4\, m$ and of negligible mass. The rod is set rotating about an axis perpendicular to its length with a uniform angular speed. The point on the rod through which the axis should pass in order that the work required for rotation of the rod is minimum is located at a distance of