An oxide of an element is a gas and dissolves in water to give an acidic solution. The element belongs to

$A$ curve passes through the point $\left(1, \frac{\pi}{6}\right)$. Let the slope of the curve at each point $(x, y)$ be $\frac{y}{x}+\sec \left(\frac{y}{x}\right)$,$x>0$. Then the equation of the curve is

Which system of classification is used by most of the world's well-known herbaria?

The number of possible enantiomeric pairs that can be produced on monochlorination of $2$-methylbutane is

Who first discovered protoplast fusion?

Which of the following organisms belongs to the Kingdom $Monera$?