How many grams of P2O5 are formed from 3.4 grams of O2

Explanation:

Electronegativity is defined as the ability of an atom to attract electrons towards itself.

And, when we move across a period in a periodic table then there occurs an increase in the electronegativity of the atoms. This is because size of atoms also decreases across the period and their nucleus is able to attract the electrons towards itself leading to an increase in the electronegativity of the atom.

Since, Na, Al, P and Cl all lie in period 3 in which sodium (Na) is located at the to left side and chlorine (Cl) is located at the extreme right side.

Therefore, electronegativity of chlorine is the strongest among the given elements.  

Thus, we can conclude that an electron will be most strongly attracted to Cl.