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Related to Chemicals: periodic table


1. pertaining to chemistry.
2. a substance composed of chemical elements, or obtained by chemical processes.


Relating to chemistry.


/chem·i·cal/ (kem´ĭ-k'l)
1. pertaining to chemistry.
2. a substance composed of chemical elements, or obtained by chemical processes.


Etymology: Gk, chemeia, alchemy
1 n, a substance composed of chemical elements or a substance produced by or used in chemical processes.
2 adj, pertaining to chemistry.

Pearl Index

Obstetrics A formula that allows comparison of the efficacy of contraceptive methods, calculated as the pregnancy rate in population divided by 100 yrs of exposure. See Breast feeding, Coitus interruptus, Condoms, Morning-after pill, Contraception, Natural family planning, Norplant, Rhythm method, RU 486.
Pearl index–pregnancies/100 years of use
Physiologic 15-30/100 years: Coitus interruptus, natural family planning (rhythm or safe period), eg calendar method, evaluation of cervical mucosa or temperature, breast feeding
Chemical 15-20/100 years: Contraceptive sponges
Barrier 2-20/100 years: Intrauterine devices, condoms
Hormonal 1-3/100 years
Surgical << 1/100 years: Ligation of fallopian tubes, vas deferens  


Relating to chemistry.


1. pertaining to chemistry.
2. a substance composed of chemical elements, or obtained by chemical processes. See also toxin.

chemical adjuvant
a chemical added to another to improve its activity. For example, mineral gels added to vaccines. May also be a chemical added to feed to improve digestion, e.g. monensin in ruminants. These are more commonly referred to as additives. See also adjuvant.
agricultural chemical
chemical used in agriculture. Includes pesticides, anthelmintics, fertilizers, algaecides, herbicides, soil fumigants and the like.
chemical environment
that part of the animals' environment that is composed of chemicals. For farm livestock this includes fertilizers, defoliants, worm drenches, insect sprays, adjuvants to feed. For companion animals see household chemical (below).
household chemical
the roster of chemicals that one can expect to find in the average household. Includes insect sprays and repellents, snail bait, rodenticide, garden sprays, human medicines and the like.
chemical pneumonitis
results from aspiration of gastric acids.
chemical senses
see olfaction (2), taste.
chemical shearing
causing the fleece of sheep to be shed by the administration of a chemical substance to the sheep. Cyclophosphamide and mimosine have been used experimentally but there is no commercially available system.
chemical spoilage
occurs in preserved foods, especially canned ones. Is usually the result of interaction between the contents and an imperfect container. There may be gas produced, e.g. hydrogen swells, or discoloration of the tin.
chemical warfare
agents used include: (1) systemic poisons, e.g. hydrocyanic acid; (2) lung irritants, e.g. chlorine, phosgene; (3) lacrimators (weeping stimulators), e.g. CN, CAP, CS; (4) sternutators (sneeze stimulators); (5) vesicants, e.g. mustards, nitrogen mustards, arsenic mustards and nettle gases; (6) nerve gases, e.g. organophosphorus compounds.

Patient discussion about chemical

Q. How do you know when depression is chemical or situational? I've been feeling frustrated lately and while I think I show some signs of depression I think it is more a feeling down because of recent changes in my life. Every time I have seen a professional they all want to start me on some drug and having really seen no improvement over the years I swore off them years ago. When is it depression or "My life sucks right now"?

A. Thank you Johanna for sharing this with us.

Q. ADHD medications work on these brain chemicals? Hope you all know about the different types of brain chemicals, so the ADHD medications work on these brain chemicals?

A. Yes Alexzander. The active ingredients in the common ADHD medications are amphetamines. The amphetamines artificially increase the amount of certain neurotransmitters in the brain, speeding up the brain (thus the term “speed” for amphetamines). This makes the frontal area more active, at least while the drug is acting.

Q. How do you tell the difference between chemical burns, and burns from fire? Please don't spare on gross words i would like to know everything there is to burns.

A. Here is a ton of info on both-

More discussions about chemical
References in classic literature ?
Let us have some fresh blood," he said, digging a long bodkin into his finger, and drawing off the resulting drop of blood in a chemical pipette.
After hours of absence, Aylmer reappeared and proposed that she should now examine his cabinet of chemical products and natural treasures of the earth.
Around the room were retorts, tubes, cylinders, crucibles, and other apparatus of chemical research.
The doctor talked of the social consequences of his chemical inquiries as if he were living in the middle ages.
All the nonsense of narrow-minded people, because he lives a retired life, and is engaged in finding out chemical secrets which the ignorant public don't know how to appreciate.
The doctor is making important chemical discoveries (the possible value of which I can appreciate, being chemical myself), and he is not quite fool enough to expose valuable secrets to the view of all the world.
As we sailed away, after procuring the necessary ingredients of our chemical fuel, the Grubittens lined the shore in silent wonder at the strange sight of our dainty craft dancing over the sparkling waters, and watched us until we were lost to their sight.
About six tattered school-books, and a few chemical books, Taxidermy, Stanley on Birds, and an odd volume of Bewick, the latter in much better preservation, occupied the top shelves.
We do not say so, because we can account for the behaviour of water by the laws of physics; and if we knew more about animals, we might equally cease to attribute desires to them, since we might find physical and chemical reactions sufficient to account for their behaviour.
It has been assumed that I used my vast chemical resources against Anne Catherick, and that I would have used them if I could against the magnificent Marian herself.
No chemical assistance was needed or used in this case.
Metal Finishing Chemicals, Global Industry Analysts

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