Which of the following property increases along a period (in general) ?

Ionization enthalpy the energy required to remove an electron from an isolated gaseous atom in its ground state. Ionization enthalpies generally increase across a period and decrease down a group. Also, in the modern periodic table, on moving from left to right across a period, the atomic size of elements decreases and the effective nuclear charge increases. Thus, the force of attraction between the nucleus and added electron increases. Hence, electron gain enthalpy becomes more negative while moving right across a period. The ionic radii of elements exhibit the same trend as the atomic radii. Hence it also decreases pn moving from left to right.