Which is element has atoms with the strongest attraction for electrons in a chemical bond

Fluorine

Explanation:

There are many variables that can affect the strenght of attraction of the electrons in a chemical bond.

The most significant of them is the electronegativity: a meassure of the affinity an element has with the electrons . The higher the electronegativity, the stronger the attraction with electrons.

The element with the highest electronegativity is Fluorine (F), been followed by Oxygen (O)

where's the diagram?

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.