Elements are arranged in groups by similar atomic structure on the periodic table. this allows for an element's properties to be predicted based on general periodic trends. one of these trends, electronegativity, increases up a group and to the right along a period and can be defined as the atom's ability to

Explanation:

Electronegativity is defined as the ability of an atom to attract an electron toward's itself from another atom.

As we move across a period, there occurs decrease in the size of atoms. As a result, force of attraction between the nucleus and valence electrons is more.

Hence, when this electronegative atom comes in contact with a metal or electron rich atom then its smaller nucelus readily attracts an electron. (As nucleus contains protons which hold a positive charge can easily attract an electron).

For example, fluorine is a highly electronegative atom and it readily attracts an electron from sodium atom when both of them comes in contact with each other.

Thus, we can conclude that electronegativity is defined as the atom's ability to attract an electron toward's itself from another atom.