What does the word polycyclic mean?
Definition of polycyclic : having more than one cyclic component especially : having two or more rings in the molecule.
Where do polycyclic aromatic hydrocarbons come from?
Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals that occur naturally in coal, crude oil, and gasoline. They also are produced when coal, oil, gas, wood, garbage, and tobacco are burned. PAHs generated from these sources can bind to or form small particles in the air.
How do you identify polycyclic aromatic compounds?
By definition, polycyclic aromatic hydrocarbons have multiple cycles, precluding benzene from being considered a PAH. Some sources, such as the US EPA and CDC, consider naphthalene to be the simplest PAH. Other authors consider PAHs to start with the tricyclic species phenanthrene and anthracene.
What are polycyclic aromatic hydrocarbons astronomy?
Polycyclic Aromatic Hydrocarbons (PAHs) are organic molecules containing two or more fused benzene rings that are arranged in a honeycomb structure with hydrogen attached to the edges of the molecule.
Which of the following is polycyclic compound?
Some examples of polycyclic organic compounds include naphthalene, anthracene, pyrene, and the benzopyrenes. A number of polycyclic hydrocarbons pose hazards to human health. For example, benzo(a)pyrene from automobile exhaust and tobacco smoke is known to be a carcinogen .
What is monocyclic in chemistry?
monocyclic (not comparable) Having a single cycle of development or activity. (chemistry) Having a single ring of atoms in the molecule; such as benzene or cyclopropane.
What are the main sources of aromatic hydrocarbons?
Simple aromatic hydrocarbons come from two main sources: Coal and petroleum. Coal is a complex mixture of a large number of compounds, most of which are long-chain compounds. If coal is heated to about 1000 °C in the absence of air (oxygen), volatile components, the so-called tar oil, are stripped out.
How many PAH compounds are there?
PAHs. PAHs, which contain two or more fused aromatic rings, constitute a broad family of compounds, many of which are mutagens and carcinogens. More than 100 different PAHs have been identified in environmental samples and 16 PAHs (Table 2) are generally measured in most exposure and environmental air pollution studies …
What foods contain PAH?
The following foods could contain PAHs:
- bivalve shellfish accumulate PAHs from seawater and sediment Limits are therefore applied to ensure that excessively-contaminated mussels or oysters do not enter the food chain.
- smoked products.
- certain cooked meat products such as flame-grilled burgers.
Which among these is the simplest example for polycyclic Arenes?
Answer: Naphthalene is simplest example for polycyclic arenes.
What is meant by polynuclear hydrocarbons?
A polynuclear aromatic hydrocarbon is a hydrocarbon made up of fused aromatic ring molecules. These rings share one or more sides and contain delocalized electrons. Another way to consider PAHs is molecules made by fusing two or more benzene rings.
What are polycyclic compounds give 2 examples?
What is a virtually polycyclic group?
A virtually polycyclic group is a group that has a polycyclic subgroup of finite index, an example of a virtual property. Such a group necessarily has a normal polycyclic subgroup of finite index, and therefore such groups are also called polycyclic-by-finite groups.
What is the collective name for a group of animals?
Collective Names for Groups of Animals. Mammals and Marsupials. Albatross: rookery. Alligators: congregation. Apes: troop or shrewdness. Baboons: troop or flange. Badgers: cete. Bats: colony or cauldron.
How do you know if a group is polycyclic?
A group is said to be polycyclic if it satisfies the following equivalent conditions: It has a subnormal series (wherein each member is normal in its successor) of finite length, starting from the trivial group and ending at the whole group, such that all the successive quotients are cyclic.
What is a metacyclic group?
A metacyclic group is a polycyclic group with n ≤ 2, or in other words an extension of a cyclic group by a cyclic group. Examples of polycyclic groups include finitely generated abelian groups, finitely generated nilpotent groups, and finite solvable groups.