Crystal radius of three ions have $100 \mathrm{pm}, 81 \mathrm{pm}$ and $75 \mathrm{pm}$, respectively. If all the three ions have the same number of protons, select the correct statement.

${\mathrm{I}}_2$ is a crystalline solid. It is a molecular solid in which ${\mathrm{I}}_2$ molecules are held together with van der Waals forces. Given diagram represents two adjacent ${\mathrm{I}}_2$ molecules in ${\mathrm{I}}_2$ solid.

If $\mathrm{A}-\mathrm{C}$ length $=6.96 \stackrel{o}{A}$ and covalent radius of iodine is $=1.33 \stackrel{o}{A}$

Find the Van der Waals radius of $\mathrm{I}$ atom.

${\mathrm{I}}_2$ is a crystalline solid. It is a molecular solid in which ${\mathrm{I}}_2$ molecules are held together with van der Waals forces. Given diagram represents two adjacent ${\mathrm{I}}_2$ molecules in ${\mathrm{I}}_2$ solid.

If $\mathrm{A}-\mathrm{C}$ length $=6.96 \stackrel{o}{A}$ and covalent radius of iodine is $=1.33 \stackrel{o}{A}$  

According to $I. C.$ Slater effective nuclear charge, $Z*,$ due to screening, is not exactly equal to the actual nuclear charge $Z$ of the nucleus of the atom.$Z*$ depends on the type of orbital In which the electron is housed, and on the ability of other electrons
in more penetrating orbitals to screen the electron in question from the nucleus.
The relative extent to which the various orbitals penetrate the electron clouds of other orbitals is$s>p>d>f.$ The effective nuclear charge $Z*$ due to screening is given by $Z^{*}=Z-\sigma$ where $Z$ is the atomic number and $\sigma$ is the slater screening constant values:$0<\sigma <Z$

Screening effect of one electron in the outermost orbital, is not considered in calculation of $\sigma .$

What is the value of $Z*$ for $\mathrm{Rb} \left(37\right)?$