Final answer:
Elements near fluorine like oxygen (O) and chlorine (Cl) are highly electronegative, with oxygen having an electronegativity of 3.5 and chlorine having an electronegativity of 3.0, both are second only to fluorine among non-metals.
Step-by-step explanation:
Elements near fluorine, such as oxygen (O) and chlorine (Cl), are also highly electronegative. Fluorine is known to be the most electronegative element with an electronegativity (EN) value of 4.0. Electronegativity tends to increase as one moves from left to right across a period in the periodic table and decrease down a group. Therefore, elements that are in the same period and closer to fluorine, like oxygen and chlorine, also have high electronegativity values.
For instance, oxygen has an EN value of 3.5, and chlorine has an EN value of 3.0, both second only to fluorine among the non-metal elements. These elements are more likely to gain electrons in chemical bonds, and as such, they form anions when they gain an extra electron. This is seen in the formation of oxide (O2-) and chloride (Cl-) ions.