Explanation:
Although fluorine is most electronegative element but chlorine has more electron gain enthalpy. This is because of the small size of the fluorine so addition of electron is not favorable process because repulsion between the electrons takes place.
The alkali metals are the most electropositive.Cesium is the most electropositive of the stable elements.
Lithium is strongest Reducing agent because of lowest standard reduction potential. When something is oxidized, it reduces another substance, becoming areducing agent. Hence lithium is the strongest reducing agent.
The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.