I think it means how many atoms is in the element im not quite sure if im right or wrong it's just a guess off the top of my head.
Roman numerals are used to identify the oxidation state of transition metals with more than one possible oxidation state.
That the charge of iron is +3 resulting in a formula of Fe2(SO4)3
The total positive charge of the cation, which is the iron ion in this case.
The Roman numeral tells you the number of electrons a polyvalent cation (usually a transition metal) gives up to participate in the ionic bond. Example: "Iron (III) oxide" means the iron is giving up 3 electrons to form the compound Fe2O3.
An exponent is a numeral used to tell how many times a number is used as a factor.
Roman numerals are used to identify the oxidation state of transition metals with more than one possible oxidation state.
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formula?
That the charge of iron is +3 resulting in a formula of Fe2(SO4)3
The total positive charge of the cation, which is the iron ion in this case.
The Roman numeral tells you the number of electrons a polyvalent cation (usually a transition metal) gives up to participate in the ionic bond. Example: "Iron (III) oxide" means the iron is giving up 3 electrons to form the compound Fe2O3.
I can't tell if that is supposed to be capital I and lower case l or roman numeral 2. A World Atlas will help you with your search.
An exponent is a numeral used to tell how many times a number is used as a factor.
The charges of the three are not a given value. They do not follow the charge patters of the Alkali/Alkali earth/ and other non metals have. Therefore, to know the charge, it must be given as a roman numeral in paranthesis () between the elements.
If you are referring to GROUP NUMBER when you say "Roman numeral above the group", it tells you the number of valence electrons, or the number of outermost electrons, with transition metals being the exception. For group number XII - XVIII the number of valence electrons is the group number minus 10 (minus 10 for the 10 transition groups).
You can tell it is an element as it is on the periodic table, as Fe, in the transition metals block.
It can tell you crtain characteristics of that element.