Neoteny refers to

The molar heat capacity of water at constant pressure is $75 \, J \, K^{-1} \, mol^{-1}$. When $1.0 \, kJ$ of heat is supplied to $100 \, g$ of water,which is free to expand,the increase in temperature of water is $...... \, K$.

If $\lim _{x \rightarrow 0}\left(\frac{\cos 4 x+a \cos 2 x+b}{x^4}\right)$ is finite,then the values of $a, b$ are respectively :

$A$ radioactive nucleus undergoes a series of decays according to the scheme:
$A \xrightarrow{\alpha} A_1 \xrightarrow{\beta} A_2 \xrightarrow{\alpha} A_3 \xrightarrow{\gamma} A_4$
If the mass number and atomic number of $A$ are $180$ and $72$ respectively,what are these numbers for $A_4$?

$A$ particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement $x$ is proportional to

The family of curves in which the sub-tangent at any point to any curve is double the abscissa is given by