According to the Bentham and Hooker system of classification,which of the following are the main divisions of the plant kingdom?

Identify the chiral molecule from the following.

The hydride ion $H^{-}$ is a stronger base than the hydroxide ion $OH^{-}$. If sodium hydride $(NaH)$ is dissolved in water,which of the following reactions will occur?

Genetic counsellors can identify heterozygous individuals by

$23 \ g$ of $Na$ metal reacts with ethanol to produce which of the following?

An earthquake generates both transverse $(S)$ and longitudinal $(P)$ waves in the earth. The speed of $S$ waves is about $4.5 \, km/s$ and that of $P$ waves is about $8.0 \, km/s$. $A$ seismograph records $P$ and $S$ waves from an earthquake. The first $P$ wave arrives $4.0 \, min$ before the first $S$ wave. The epicenter of the earthquake is located at a distance of about ..... $km$.