Question

why electron gain enthalpy of flourine is less negative than that of chlorine?

Answer 1

this is coz of the fact that fluorine has a smaller size and has the more tendency to attract an electron whereas in case of chlorine the size increases which affects the tendency to attract an electron

Answer 2

flourine is the most electronegative element.it has 9 electrons in its shell..to gain noble gas configuration it easile loses one electron.