What is the membrane surrounding the heart called?

Which of the following hydrides has the lowest boiling point?

In which of the following reactions,the concentration of the product is higher than the concentration of reactant at equilibrium? ($K =$ equilibrium constant)

$A$ plano-convex lens fits exactly into a plano-concave lens. Their plane surfaces are parallel to each other. If the lenses are made of different materials with refractive indices $\mu_1$ and $\mu_2$ and $R$ is the radius of curvature of the curved surface of the lenses,then the focal length of the combination is:

The product of the lengths of perpendiculars drawn from any point on the hyperbola $x^2 - 2y^2 - 2 = 0$ to its asymptotes is:

The energy of a photon is $3 \times 10^{-12} \ erg$. What is its wavelength in $nm$?
$(h = 6.62 \times 10^{-27} \ erg \cdot s; c = 3 \times 10^{10} \ cm/s)$