Which of the following is a biodegradable polymer?

If $P(n,r) = 1680$ and $C(n,r) = 70$,then $69n + r! = $

What is the ratio of the rate of diffusion of oxygen $(O_2)$ and hydrogen $(H_2)$?

For a gas,$\frac{R}{C_{V}}=0.4$,where $R$ is the universal gas constant and $C_{V}$ is the molar specific heat at constant volume. The gas is made up of molecules which are

If the equilibrium constant for the reaction,$H_{2(g)} + I_{2(g)} \rightleftharpoons 2 HI_{(g)}$ is $K$,what is the equilibrium constant of $HI_{(g)} \rightleftharpoons \frac{1}{2} H_{2(g)} + \frac{1}{2} I_{2(g)}$?

Which of the following oxides is amphoteric?