Why is it that elements with high electronegativity are acidic?

Question

what makes something basic amphoteric or acidic???

Pretend i'm stupid... wait there's no need to pretend...

Answer 1

When it comes to acid and bases, there are three basic definitions

Arrehenius theory - acids donate H+ and bases donate OH- in an aqueous solutions (ions dissolved in water)

Bronsted - Lowery - acids are proton donors, while bases accept protons (allows for non H+ or OH- species like NH3 or Cl-)

Lewis definition - acids accept electron pairs while bases donate electron pairs

The most important is the Lewis definition because it is the broadest definition that allows the widest range. It also explains whey elements with high electronegativities ( the ones to the right and closet to the top) because they are the elements most likely to accept electron pairs. They want to accept electron pairs to fill their valence shells (outside orbitals if you know what those are...)

Amphoteric species just means that they can be either an acid or a base. To clarify if something can be amphoteric or not, you can look at the three definitions. For instance, according to Bronsted-Lowery, water can be either an acid or base, it can gain a proton and become H3O+ or lose an electron and become OH-.

Typically, hydroxides of certain metals like Al, Zn, Pb, or Cr can be amphoteric. Chances are if you are uncertain, if it has a Hydrogen and is a negative ion, it could gain another Hydrogen or lose the one it has (according to Arrenhious it is amphoteric)

HSO4- can lose H to become SO4-2

HSO4- can gain H to become H2SO4

hope that is not too confusing