Why is copper(II) carbonate CuCO3 and not Cu2CO3?

[ruby]

Also,
Why is SnCl4 tin(IV) chloride and not tin chloride?
Why is HIO4 periodic acid and not iodic acid?
Why is SF6 sulfur hexafluoride and not monosulfur hexafluoride?
Why is AlF3 aluminum trifluoride and not aluminum(III) fluoride?

[therobot]

copper (II) has a charge of 2+ and Carbonate also has a charge of 2-
so they give the same amount of electrons to each other so the 2 is not supposed to be there

SnCl4 tin(IV) chloride and not tin chloride because when you cross over the charges and Cl has a charge of 1- so that means that Sn has a charge of 4+ because to get the compound you must cross over the charges thats why there is a 4 next to chlorine

Why is AlF3 aluminum trifluoride and not aluminum(III) fluoride?
the roman numerals are only applied to the elements that can have more than one charge but Aluminum has only one charge which is 3+ and when it is combined with Fluorine you cross over the charges which gives the Fluorine the 3 and Aluminum gets the Fluorines charge which is 1- when its either a 1- or a 1+ you don't write Al1F3 you write AlF3

[Mensamedlem]

Yes it is.

[dyadak]

right thanks