Which of the following compounds does not contain a peroxide ion?

Which of the following is the most important cause driving animals and plants to extinction?

$A$ particle of mass $m$ is moving in a circular path of constant radius $r$ such that its centripetal acceleration $a_c$ is varying with time $t$ as $a_c = k^2rt^2$. The power delivered to the particle by the forces acting on it is

During which phase of the cell cycle are the proteins and microtubules required for mitosis synthesized?

The solution of the differential equation $\frac{dy}{dx} = \sin(x+y) \tan(x+y) - 1$ is

The two surfaces of a concave lens,made of glass of refractive index $1.5$,have the same radii of curvature $R$. It is now immersed in a medium of refractive index $1.75$. Then the lens: