Atomic & Molecular Symbols: What Do They Mean?

In summary, atomic and molecular symbols are shorthand notations used to represent elements and molecules in chemistry, determined by the element's atomic number or the composition and arrangement of atoms in a molecule. The numbers and letters in the symbols represent the number of atoms or ions and the element's chemical symbol. These symbols are derived from the periodic table, and there are exceptions and variations to consider, such as alternative notations for isotopes and ions and different chemical symbols in different languages.
  • #1
filippo
12
0
Atoms have Terms Symbols such as S (L=0), P (L=1), D (L=2), etc...In case of molecules, L no longer exists as other symbols are uesd: which ones?
 
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  • #2
filippo said:
Atoms have Terms Symbols such as S (L=0), P (L=1), D (L=2), etc...In case of molecules, L no longer exists as other symbols are uesd: which ones?

I often see: Sigma [itex]\Sigma[/itex], Pi [itex]\Pi[/itex], etc. Often with a subscript g or u. The meaning are given in various books. For example, Landau and Lifgarbagez "Quantum Mechanics".
 
  • #3


I can provide a response to the question of atomic and molecular symbols and their meanings. The symbols used to represent atoms, such as S, P, D, and others, are known as spectroscopic notation and are used to describe the electron configuration of an atom. The letters represent the different orbital shapes (S = spherical, P = dumbbell, D = cloverleaf, etc.) and the number following the letter represents the energy level or shell in which the electrons reside.

When it comes to molecules, the concept of orbital shapes and energy levels becomes more complex. The L symbol, which represents the orbital angular momentum quantum number, is no longer used in molecular notation. Instead, symbols such as sigma (σ), pi (π), and delta (δ) are used to describe the different types of bonds between atoms in a molecule.

Sigma bonds (σ) are formed when two atomic orbitals overlap end-to-end, creating a single bond. Pi bonds (π) are formed when two atomic orbitals overlap side-by-side, creating a double bond. Delta bonds (δ) are formed when four atomic orbitals overlap, creating a triple bond. These symbols are also used to describe the hybridization of atomic orbitals in a molecule.

In summary, while the symbols used to represent atoms and molecules may seem confusing, they are based on scientific principles and are essential in understanding the structure and properties of matter. By using spectroscopic and molecular notation, scientists can communicate complex information about atoms and molecules in a concise and standardized way.
 

1. What are atomic and molecular symbols?

Atomic and molecular symbols are shorthand notations used to represent elements and molecules in chemistry. They consist of one or two letters, often derived from the element's name, and may also include subscripts and superscripts to indicate the number of atoms or ions present.

2. How are atomic and molecular symbols determined?

The atomic and molecular symbols for elements are determined by their atomic number, which corresponds to the number of protons in the nucleus. For molecules, the symbols are determined by the composition and arrangement of atoms within the molecule.

3. What do the numbers and letters in atomic and molecular symbols represent?

The numbers in atomic and molecular symbols represent the number of atoms or ions of each element present in a molecule. The letters represent the element's chemical symbol, which is usually the first one or two letters of its name.

4. How do atomic and molecular symbols relate to the periodic table?

The periodic table is organized based on the atomic number and chemical properties of elements. The atomic and molecular symbols for elements are derived from their position on the periodic table. Additionally, the periodic table can be used to determine the number of protons, neutrons, and electrons in an atom based on its symbol.

5. Are there any exceptions or variations to atomic and molecular symbols?

There are a few exceptions and variations to atomic and molecular symbols, such as the use of different chemical symbols for the same element in different languages (e.g. Fe for iron in English and Fe for ferrum in Latin). Additionally, some elements have multiple symbols, such as carbon having both C and CO2 for carbon dioxide. There are also alternative notations used for isotopes and ions, such as 14C and C- for carbon-14 and carbonate ion, respectively.

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