An open vessel at $300 \ K$ is heated until $2/5$ of the air in it has been expelled. Assuming the volume of the vessel remains constant,find the temperature to which the vessel has been heated in $K$.

Which of the following is concerned with eubacteria?
$(1)$ Methanogens $(2)$ Anabaena $(3)$ $N_2$ fixation $(4)$ Thermoacidophiles $(5)$ Eukaryotes $(6)$ Diatoms $(7)$ Gelatinous sheath $(8)$ Heterocyst

The focal distance of a point on the parabola $y^2 = 16x$ whose ordinate is twice the abscissa,is

An infinitely long thin straight wire has a uniform linear charge density of $\frac{1}{3} ~Cm^{-1}$. The magnitude of the electric field intensity at a point $18 ~cm$ away is (given $\varepsilon_0 = 8.85 \times 10^{-12} ~C^2 N^{-1} m^{-2}$):

Which of the following molecules does not have a linear arrangement of atoms?

The formula of azurite is