roman numeral

Examples of roman numeral in the following topics:

• Writing Lewis Symbols for Atoms

  • Some periodic tables list the group numbers in Arabic numbers instead of Roman numerals.
  • The corresponding roman numerals used are I, II, III, IV, V, VI, VII, VIII.
  • Group numbers shown by Roman numerals (above the table) tell us how many valence electrons there are for each element.

• Electron Configuration of Cations and Anions

  • In the case of transition metals, oxidation states can be specified with Roman numerals; for example, Fe2+ is occasionally referred to as Fe(II) or FeII.
  • The Roman numeral designates the formal oxidation state of an element, whereas the superscripted numerals denotes the net charge.
  • The two notations are therefore exchangeable for monatomic ions, but the Roman numerals cannot be applied to polyatomic ions.

• Naming Coordination Compounds

  • The oxidation number appears as a Roman numeral in parenthesis after the cation.
  • (Numerical prefixes do not affect the order.)
  • If the central atom's oxidation state needs to be specified (when it is one of several possible, or zero), write it as a Roman numeral (or 0) in parentheses.

• Ions

  • Monoatomic ions are sometimes also represented by Roman numerals, which designate the formal oxidation state of the element, whereas the superscripted numerals denote the net charge.
  • These representations can be thought of as equivalent for monoatomic ions, but the Roman numerals cannot be applied to polyatomic ions.

• Naming Ionic Compounds

  • For cations that take on multiple charges (typically transition metals), the charge is written using Roman numerals in parentheses immediately following the element name.
  • The Roman numerals in fact show the oxidation number, but in simple ionic compounds this will always be the same as the metal's ionic charge.

• Oxidation Numbers of Metals in Coordination Compounds

  • The oxidation number for metals that can have more than one oxidation state is represented by a Roman numeral.

• Sulfur Compounds

  • The sulfur oxides form numerous oxyanions with the formula SOn2–.
  • Phosphorus sulfides are numerous.
  • Because of the heat and sulfur, the process was named vulcanization, after the Roman god of the forge and volcanism.

• Strategy for General Problem Solving

  • A unit will cancel out if it appears in both the numerator and the denominator during the equation.
  • If the units are ignored, the quotients do not numerically equal 1, but 1/12 or 12.
  • However, with the inclusions of the units, both the numerators and denominators describe the exact same length, so the quotients are equal to 1.
  • It does not change the equation, only the relative numerical values within the various units.
  • In the first equation, the unit (feet) is in both the numerator and denominator of the expression, so they cancel.

• Naming Hydrates

  • The name of a hydrate follows a set pattern: the name of the ionic compound followed by a numerical prefix and the suffix -hydrate.
  • The name of a hydrate follows a set pattern: the name of the ionic compound followed by a numerical prefix and the suffix "-hydrate."

• Diazo Ketone Reactions

  • If we assume that diazo ketones normally decompose to acyl carbenes, then numerous subsequent reactions can be imagined, and many have been realized.