Floral formula of Cruciferae (Brassicaceae) is$-$

Saponification is

During transcription,the holoenzyme $RNA$ polymerase binds to a $DNA$ sequence,and the $DNA$ assumes a saddle-like structure at that point. What is that sequence called?

For the Bohr's first orbit of circumference $2\pi r$,the de-Broglie wavelength of the revolving electron will be

Why does copper not replace hydrogen from acids?

$A$ and $B$ are two radioactive substances whose half-lives are $1$ and $2$ years respectively. Initially, $10 \, g$ of $A$ and $1 \, g$ of $B$ are taken. The time (approximate) after which they will have the same quantity remaining is ........... $years$.