All metals form basic oxides. Metallic oxides are basic in character.
Polonium is a metal, so it should form basic oxides but it forms acidic oxides. Why are its oxides acidic in character?
All metals form basic oxides. Metallic oxides are basic in character.
Polonium is a metal, so it should form basic oxides but it forms acidic oxides. Why are its oxides acidic in character?
All metals form basic oxides.
That's true. I cannot remember metal, that does not form basic oxide
Metallic oxides are basic in character.
Not necessary. Polonium is not the only one metal, forming acidic oxides. Mn, Cr and some others do it as well.
Oxide is considered acidic, when it forms hydroxide, that is acidic (well, it is simplification, but let's stick with it for a while). Hydroxide is acidic, when it can lose proton, giving stable anion. Acidity of hydroxide and metallicity of element formed it does not connect any way. Acidity depends of ability of remaining part of molecule to stabilize negative charge, which usually correlate with $\ce{O/OH}$ ratio and electronegativity of central atom. So, $\ce{H6TeO6}$ is quite weak acid and $\ce{H2CrO4}$ or $\ce{HMnO4}$ are quite quite strong acids.
Another way of looking at this is to understand that the structure is always
$$\ce{M-O-H}$$
where $\ce{M}$ is the metal atom. If the $\ce{O-H}$ bond is weaker than the $\ce{M-O}$ bond, the material acts as an acid. Otherwise it acts as a base.
What determines the relative strength is a bit complex. Suffice it to say that it depends on oxidation state of the $\ce{M}$ atom as well as the constituents in the rest of the molecule and the environment all play a role.
Some materials are amphoteric. That is they can split either way. A typical example is aluminum hydroxide, $\ce{Al(OH)_3}$, which has three $\ce{O-H}$ bonds. It is usually a base, but under the right conditions it breaks the other way and is a weak acid called aluminic acid. The formula for that is usually written as $\ce{H3AlO_3}$, but the structure is the same.
While virtually all metals from a basic oxide or amphoteric (reacts with both bases and acids) oxide like aluminium and both Tin(II) and Tin(IV), some also form acidic oxides like Chromium(VI) oxide, Iron(II) oxide. With oxides its better to describe they according to their reactivity with acids and bases as you are not trying to convert them to the hydrate.
Its not incredible for Polonium to form only an acid oxide.