When an ionic bond is formed, what type of atom (in terms of relative electronegativity) is likely to: a) lose one or more electrons? b) gain one or more electrons? Explain your reasoning.

Electronegativity is a measure of how strongly an atom can attract and hold onto electrons when it bonds with another atom. It's a crucial concept in chemistry that explains a lot about how and why different types of bonds form between elements. Atoms with high electronegativity, such as non-metals, are like the strong kids in a game of tug-of-war—they're likely to pull electrons towards themselves and away from less electronegative atoms, usually metals.

Understanding electronegativity can also help predict the polarity of bonds, where polar bonds occur between atoms with different electronegativities. For instance, in a water molecule, oxygen has a higher electronegativity than hydrogen, hence it has a partial negative charge, while hydrogen has a partial positive charge. This difference leads to polar covalent bonding, which is a bit different from the ionic bonding we see when one atom actually loses electrons to another.

When atoms lose electrons, they become positively charged ions, known as cations. This is a typical trait of metals since they have a lower electronegativity and fewer electrons in their outermost shell. It's easier for them to give up these outer electrons than to gain more to fill the shell.

In the grand scheme of the periodic table, we find that elements on the left side, such as sodium (Na) and potassium (K), often lose electrons during reactions. The loss of electrons is not just a happenstance but a crucial process to achieve chemical stability, akin to 'finding zen' in the chaotic world of chemical interactions. For metals, losing electrons leads to that sought-after stability resembling the nearest noble gas configuration.

At the other end of the spectrum, we have atoms that gain electrons, forming negatively charged ions, or anions. This characteristic is common among non-metals, which have higher electronegativity and a greater number of electrons in their valence shell. Pulling in extra electrons allows these atoms to complete their outer shell, achieving chemical stability.

Take chlorine (Cl) for example. It's just one electron shy of being as stable as noble gases, so it's very 'eager' to accept an electron from another atom. When it does, it achieves a full valence shell and becomes a chloride ion (Cl-). This gaining of electrons is like completing a puzzle—you might already have most of the pieces, but you need that last piece from somewhere else to complete the picture. In essence, non-metals can be seen as puzzle enthusiasts, always on the lookout for that missing electron to complete their valence shell.