14. Electronegativity: Trends in the modern periodic table

  

  

By going from top to bottom, the tendency to lose electrons by an atom increases.

 

  

On moving from left to right, the tendency to loses an electron by an atom decreases.

 

The tendency to lose electrons decreases with increasing effective nuclear charge acting on valence shell electrons over a period. Because the outermost electrons are so far away from the nucleus, the effective nuclear charge experienced by valence electrons decreases down the group. Hence, these can be lost easily. Therefore, the metallic character decreases over the period and increases down a group.

 

Non-metals, on the other hand, are electronegative. They are more likely to form bonds if they gain electrons. Let's see how this property differs from others.

 

  

 

 

The tendency of gaining electrons increases as you move from left to right over a period.

 

  

The tendency to gain electrons decreases as you move down in a group.

 

As the trends in electronegativity show, non-metals are found on the right-hand side of the periodic table towards the top.

 

These trends also help us predict the nature of the oxides produced by the elements because you already know that metal oxides are basic and non-metal oxides are acidic.