Fe is the polyvalent ion in this.
It is an ion that has multiple charges
The chemical formula of hydronium ion is (H3O)+.For the "oxide ion" check your spelling.
The positive ion in calcium oxide is the calcium ion (Ca^2+), which has lost two electrons. The negative ion in calcium oxide is the oxide ion (O^2-), which has gained two electrons.
The formula for the oxide ion is O2-, and the formula for the nitrate ion is NO3-.
An oxide ion has 8 protons. This is because it is an oxygen atom that has gained 2 electrons to become negatively charged. The number of protons remains the same as the number of protons in a neutral oxygen atom.
polyvalent atom
The noble gas that is isoelectronic with the oxide ion O2 is neon (Ne). Both the oxide ion O2 and the neon atom have 10 electrons.
The polyatomic ion oxide is O2-, which consists of two oxygen atoms with a charge of -1. This ion is commonly found in compounds such as magnesium oxide (MgO) and carbon dioxide (CO2). Oxoanions containing oxygen and other elements can also form polyatomic ions with the oxide ion.
FeBr3
Oxide ion (O2-) is isoelectronic with neon. Both species have the same number of electrons, which is 10.
FeO (iron oxide . it's another name) The correct answer is Iron(III)oxide which is Fe2O3
Oxide - O2- electronic configuration of oxygen atom: 1s2, 2s2 2p4. electronic configuration of oxygen ion: 1s2, 2s2 2p6. phosphate - PO43-