Which of the following statements are correct?
A. The process of adding an electron to a neutral gaseous atom is always exothermic.
B. The process of removing an electron from an isolated gaseous atom is always endothermic.
C. The 1st ionization energy of boron is less than that of beryllium.
D. The electronegativity of C is 2.5 in ${\rm{C}}{{\rm{H}}_4}$ and ${\rm{CC}}{{\rm{l}}_4}$
E. Li is the most electropositive among elements of group I .
Choose the correct answer from the options given below: