Which oxide of nitrogen is obtained when ammonium nitrate is heated at $250\,^oC$?

Which of the following can have a structure with $sp^3$ $C$ atoms only?

Cardiac output is determined by which of the following?

When $10 \ g$ of methane is completely burnt in oxygen,the heat evolved is $560 \ kJ$. What is the heat of combustion (in $kJ \ mol^{-1}$) of methane?

Lenz's law is a consequence of the law of conservation of:

Planet $M$ orbits around its sun,$S$,in an elliptical orbit with the sun at one of the foci. When $M$ is closest to $S$,it is $2 \ unit$ away. When $M$ is farthest from $S$,it is $18 \ unit$ away. Assuming $S$ is at the origin $(0, 0)$ and the other focus lies on the negative $y$-axis,find the equation of the elliptical orbit of planet $M$.