The correct formula of diammine dichlorodicyanochromate$(III)$ ion is

$A$ point object on the principal axis at a distance $15\, cm$ in front of a concave mirror of radius of curvature $20\, cm$ has a velocity of $2\, mm/s$ perpendicular to the principal axis. The velocity of the image at that instant will be.......$mm/s$.

$\int [\sin (\log x) + \cos (\log x)] \;dx = $

$\int_0^{2 \pi} \sin^6 x \cos^5 x \, dx$ is equal to

Lithium shows similarities to magnesium in its chemical behaviour because

The equivalent mass of an element is $4$. Its chloride has a vapor density of $59.25$. What is the valency of the element?