When are roman numerals used in chemical formulas?

Answer 1

The Roman numeral is the metal’s oxidation state used as the subscript on the nonmetal in the crisscross method. -Apex

Answer 2

They are used in chemical formulas when Roman numerals are used to identify the Charge ( oxidation state) on an ion. They are used on elements that have more than one possible charge., such as Tin which can be +2 or +4.

Answer 3

Roman numerals are used to identify the Charge ( oxidation state) on an ion. They are used on elements that have more than one possible charge., such as Tin which can be +2 or +4.

SnCl4 Cl = -1, so Sn = +4

Name Tin IV chloride

Answer 4

When the element has more than one ion charge(check the periodic table) because u need to specify which charge is being used if there's more than one. Ex) manganese oxide. We need to know what ion charge is on manganese as there could be 2+ 3+ or 4+. If it's manganese(IV)oxide then we know the answer!!= Mn2O4. Ps. The 2 comes from oxygen. We know it's 2 bcuz it's the only ion charge O has:)

Answer 5

Where the oxidation state of the cation (e.g. metal) can have multiple values as in in iron which may be Fe2+ or Fe3+ then to distinguish the two iron oxides:-

FeO iron(II) oxide

Fe2O3 iron(III) oxide

When there is only one oxidation state as in sodium then there is no need for roman numerals

NaCl is sodium chloride not sodium(I) chloride

where there are mixed oxidation states of an element as in Fe3O4 which contains Fe2+ and Fe3+ then both oxidation states are shown

Fe3O4 iron (II,III) oxide.

Answer 6

When naming compounds which contain transition elements.

Answer 7

The roman numeral is the metal's oxidation state used in the crisscross method.

Answer 8

They depicts the group number. The groups are made according to the chemical properties of elements. They are the vertical columns in the Periodic Table.

Answer 9

The Roman numeral is the indication of valence.