Why does electronegativity increase across a period? Consider sodium at the beginning of period 3 and chlorine at the end (ignoring the noble gas, argon). Electronegativity increases across a period because the number of charges on the nucleus increases. That attracts the bonding pair of electrons more strongly.
Besides, what is the trend in electronegativity across Period 3?
Explanation of this trend the nuclear charge increases … the atomic radius decreases … there are more electrons, but the increase in shielding is negligible because each extra electron enters the same shell … so electrons will be more strongly attracted to the nucleus.
Subsequently, question is, why does conductivity decrease across Period 3? Explanation of this trend They have metallic bonding, in which the nuclei of metal atoms are attracted to delocalised electrons. Going from sodium to aluminium: there are more electrons that can move and carry charge through the structure … the electrical conductivity increases.
Keeping this in view, why does electronegativity increase across a period and decrease down a group?
So, as you move down a group on the periodic table, the electronegativity of an element decreases because the increased number of energy levels puts the outer electrons very far away from the pull of the nucleus. Electronegativity increases as you move from left to right across a period on the periodic table.
Why are some atoms more electronegative than others?
Electronegativity is the ability of an atom to pull electrons towards itself. Some atoms are better at doing this than others. Atoms with more protons in the nucleus, tend to have higher electonegativities, because the positive nuclear charge is higher and therefore, it can pull more electrons towards it.