Sodium
It is refered to as the Elements symbol.
Many chemical elements have a two letter symbol.
The one or two letter short form is called the symbol for the element.
Elements are abbreviated by one or two letters. Most elements are abbreviated by one letter, but some elements are abbreviated by two letters, typically when the one-letter abbreviation is already taken by another element.
If the first letter is in Capitals and the second letter isn't, it is simply the name of one Element e.g. Feis Iron. If both the second and the first letters are in Captials there are two elements. e.g. CO which is Carbon Monoxide.Brad, U.K.
In the system of symbols for elements, each element is represented by one or two letters derived from its name. For example, W is the symbol for tungsten, derived from its German name "Wolfram." Similarly, Hg is the symbol for mercury, derived from its Greek name "hydrargyrum." These symbols are used universally to represent elements in the periodic table.
name and give the symbol of 2 radio active elements
While giving symbols to the elements the first letter of the name of the element was used. But in case of two or more elements with same initial the next elements were given symbols containing first two letters. Since boron has symbol B, so bromine got the symbol Br.
Xenon has the chemical symbol Xe.
Having a second letter in the symbol for elements is necessary to distinguish elements with similar symbols. It helps identify the specific element and avoid confusion when referencing or working with different elements.
In the periodic table of elements, there is no element represented by the letter "J." The elements are typically represented by one or two-letter chemical symbols that are based on their English name or Latin name.
The abbreviation of an element's name is called its chemical symbol, which is a one or two-letter representation used to identify elements in the periodic table. For example, the chemical symbol for oxygen is "O" and for hydrogen is "H."