Question

The most reactive non-metal is:

• A. R
• B. S
• C. P
• D. U

Answer 1

The correct option is A R

First ionisation enthalpy is the energy required to remove an electron from a neutral atom while second ionization enthalpy is the energy required to remove an electron from a +1 cation or a positively charged ion ( in other words one electron is already removed, we have to remove another electron)

Electron gain enthalpy is the energy released when an electron is added to an isolated gaseous atom.

Reactivity and ionisation enthalpy are directly related. The high is the ionization enthalpy the more reactive the element is.

In the following question R has the highest energy and as a result it is highly reactive. Also R releases more energy. So its electron gain enthalpy is also high. Rest all elements have less enthalpies than R and as a result they are less reactive than R.

Hence the correct option is 'A'