Which one of the following salts gives an acidic solution in water?

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

The Poisson's ratio of a material is $0.5$. If a force is applied to a wire of this material,there is a decrease in the cross-sectional area by $4 \%$. The percentage increase in the length is ........ $\%$

Which of the following statements is incorrect?

Identify $B$ in the following reaction:
$H_4SiO_4$ $\xrightarrow[1000^{\circ}C]{-2H_2O} A$ $\xrightarrow[\Delta]{\text{Carbon}} B + CO$

The vector $c \cdot (b+c) \times (a+b+c)$ is equal to