In HTML 5, what was previously called block-level content is now called flow content. The element is often used to indicate an implicit or explicit contrast. Use the element to mark text that has greater importance than surrounding text. Use the element to mark the title of a work (book, play, song, etc.) it is also typically styled with italic type, but carries different meaning. However, it should not be used simply to apply italic styling use the CSS styling for that purpose. Typically this element is displayed in italic type. This element only includes the global attributes. HTMLElement Up to Gecko 1.9.2 (Firefox 4) inclusive, Firefox implements the HTMLSpanElement interface for this element. None, both the starting and ending tag are mandatory.Īny element that accepts phrasing content. Content categoriesįlow content, phrasing content, palpable content The element can be nested, with each level of nesting indicating a greater degree of emphasis. So, the symbol for tennessine is Ts and not Tn, which closely resembles the state abbreviation TN.The HTML element marks text that has stress emphasis. Sometimes this is because the symbol is too close to another well known abbreviation or else the name doesn't follow other conventions. The name and symbol aren't always approved. Once an element discovery is confirmed, the person or lab responsible for the discovery submits a proposed name and symbol to the IUPAC.In the past, this has led to considerable controversy, as the identity of the discoverer has been debated. In order for an element to get an name, its discovery must be verified. Elements are named by their official discoverer.

Examples include einsteinium (named for Albert Einstein), californium (named for California), helium (named for the sun god Helios), and calcium (named for the mineral calyx). Newly discovered elements may be named for a person, place, mythological reference, property, or mineral.The exception to this rule is the name of helium, which predates the convention. Examples include neon, krypton, and oganesson. Examples include chlorine, bromine, astatine, and tennessine. Halogen element names have an -ine ending.An example is the symbol for chromium, which is Cr. Element symbols are one- or two-letter symbols.When the IUPAC name is used, it is written in lowercase letters unless the name begins a sentence. So, Germans may call hydrogen 'Wasserstoff' for 'water substance' or nitrogen may be called 'Stickstoff' for 'smothering substance.' People who speak romance languages called nitrogen 'azote' or 'azot' from words which mean 'no life.' For example, the name for gold is universal, but its symbol is Au, which reflects an earlier name of aurum. Some of these regional differences converged into accepted names, but old symbols persist.

People had various names for true elements. The earliest elements included things that were mixtures, such as air and fire. Most other element names end with -ium.Įarly humans couldn't distinguish between elements and compounds. Except for helium, noble gas names end with -on.

Some element groups have naming conventions.

Then, a name and symbol may be proposed by the discoverer.

Elements don't gain official names and symbols until after their discovery has been verified.

However, elements often have common names and symbols in various countries.

Official element names and symbols are determined by the International Union of Pure and Applied Chemistry (IUPAC).

Na element name