Answer 1 : The 'Cesium' element on the periodic table is the "best loser" of electrons.
Explanation :
The metals has the tendency to lose the electrons easily than the non-metals.
In all the metals, group 1 elements has more tendency to lose an electron easily than the group 2 elements.
As we know, the all elements in group 1 have one valence electron in their outermost shell. As we go down in a group, the number of shells increases and the valence electrons are away from the nucleus and less tightly bound the electrons to it.
Ionization energy : It is defined as the less amount of energy is required to remove the electron from their valence shell.
As we go down the group, the ionization energy decreases.
Hence, the 'Cesium' element on the periodic table is the "best loser" of electrons.
Answer 2 : The 'Fluorine' element on the periodic table is the "best gainer" of electrons.
Explanation :
The non-metals has the tendency to gain the electrons easily than the metals.
In all the non-metals, group 17 elements has more tendency to gain an electron easily than the group 15 and group 16 elements.
As we know, the all elements in group 17 have seven valence electrons in their outermost shell. As we go down in a group, the atomic size and nuclear charge increases which decreases the attraction of the incoming electron to the nucleus. Therefore, the electron gain enthalpy become less negative as we go down the group.
Hence, fluorine is the most electronegative element in the periodic table.