Fluorine is known as the most electronegative element on the periodic table. That's a fancy way of saying it really loves to grab onto electrons. Let me explain why that is in a simple way.

1. Atomic Structure: Fluorine has an atomic number of 9. This means it has 9 protons in its center, called the nucleus. The more protons there are, the stronger the positive charge. This strong charge helps fluorine pull in electrons better than many other elements.

2. Electron Configuration: Fluorine’s list of electrons is $1s^2 2s^2 2p^5$. This means it has 7 electrons in its outer layer. It is only 1 electron away from having a full shell, which would be $2s^2 2p^6$. Because of this, fluorine really wants to gain that one extra electron to feel stable.

3. Position in the Periodic Table: Fluorine is in group 17, which is known as the halogens. Since it is at the top of this group, it has less interference from other electrons. This means it can pull in extra electrons even more strongly than bigger atoms.

All these reasons help explain why fluorine is super good at attracting electrons. That’s why it has the title of the most electronegative element!