The number of radial nodes of $3s$ and $2p$ orbitals respectively are

Every planet revolves around the sun in an elliptical orbit. Consider the following statements:
$A.$ The gravitational force acting on a planet is inversely proportional to the square of the distance from the sun.
$B.$ The gravitational force acting on a planet is inversely proportional to the product of the masses of the planet and the sun.
$C.$ The centripetal force acting on the planet is directed away from the sun.
$D.$ The square of the time period of revolution of a planet around the sun is directly proportional to the cube of the semi-major axis of the elliptical orbit.
Choose the correct statements from the options given above:

$A$ liquid does not wet the solid surface if the angle of contact is

What is the hybridization state of the central atom in the conjugate base of $NH_4^{+}$ ion?

$A$ bucket tied at the end of a $1.6\, m$ long string is whirled in a vertical circle with constant speed. What should be the minimum speed so that the water from the bucket does not spill,when the bucket is at the highest position? (Take $g = 10\, m/sec^2$)

The point on the curve $y^{2}=2(x-3)$ at which the normal is parallel to the line $y-2x+1=0$ is