The number of acidic hydrogen atoms in $but-1-yne$ is ........

Solid $NaCl$ is a bad conductor of electricity because

In any $\triangle ABC$,$r_1 r_2 + r_2 r_3 + r_3 r_1$ is equal to

The potential energy of a particle of mass $m$ is given by $U(x) = \begin{cases} E_0; & 0 \le x \le 1 \\ 0; & x > 1 \end{cases}$. $\lambda_1$ and $\lambda_2$ are the de-Broglie wavelengths for $0 \le x \le 1$ and $x > 1$ respectively. If the total energy of the particle is $2E_0$,the ratio $\frac{\lambda_1}{\lambda_2}$ will be

$A$ number $n$ is chosen at random from $\{1, 2, 3, 4, \ldots, 1000\}$. The probability that $n$ is a number that leaves remainder $1$ when divided by $7$ is:

The radius of Germanium $(Ge)$ nuclide is measured to be twice the radius of $_{4}^{9}\text{Be}$ . The number of nucleons in $Ge$ are