Math Is Fun Forum

Co-operation Quotes

1. If you will work in co-operation, forgetting the past, burying the hatchet, you are bound to succeed. - Muhammad Ali Jinnah

2. Stop-and-search has the potential to cause immense resentment and honesty to the police, with all the implications that has for generating distrust and ending co-operation from the public, if it is not used fairly. - Theresa May

3. A sincere and steadfast co-operation in promoting such a reconstruction of our political system as would provide for the permanent liberty and happiness of the United States. - James Madison

4. There is no doubt that this government and this country are benefiting from the reforms that we brought in the 1980s, and that couldn't have been done without the co-operation of the trade union movement. - Bob Hawke

5. I want Infosys to be a company which is globally respected and in where people belonging to different nationalities, races and religious beliefs will work with intense competition but utmost courtesy, dignity and co-operation in adding greater value to our stakeholders day after day. - N. R. Narayana Murthy

6. We are ready to engage in international co-operation against terrorism with a view to safeguarding national interests and regional security and stability. - Li Peng

7. Europe has found itself confronted with fresh challenges - challenges of a global character, the nature of which is directly connected with changes in the international climate and the difficulties of seeking new models for co-operation. - Boris Yeltsin

8. We can realise a lasting peace and transform the East-West relationship to one of enduring co-operation. - George H. W. Bush

9. If co-operation is a duty, I hold that non-co-operation also under certain conditions is equally a duty. - Mahatma Gandhi.

Q: What kind of apple has a short temper?
A: A crab apple.
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Q: What do you get when you cross an apple with a Christmas tree?
A: Pineapple.
* * *
Q: What is the left side of an apple?
A: The part that you don't eat.
* * *
Q: How do you make an apple puff?
Chase it round the garden.
* * *
Q:  What do you get if you cross a jogger with an apple pie ?
A: Puff pastry !
* * *

Q: Why did the apple stop in the middle of the road?
A: Because he ran out of juice.
* * *
Q: What did the worm want to do when he grew up?
A: He wanted to join the Apple Core (Corps).
* * *
Q: What do you call a fruit that is rough around the edges?
A: A bad apple.
* * *
Q: What do you say when a fruit wins the talent show?
A: How about them apples?
* * *
Q: Dad, do you like baked apples?
A: Yes son, why?
Q: The orchard's on fire.
* * *

Rutherfordium

Gist

Rutherfordium (Rf) is a synthetic, highly radioactive chemical element with atomic number 104, found in group 4 of the periodic table. It does not occur naturally and must be created in a laboratory through nuclear reactions in particle accelerators. Named after physicist Ernest Rutherford, its properties are difficult to study because it has a very short half-life, with the most stable known isotope 267Rf lasting about 48 minutes.

Because rutherfordium is made within the lab, there are not very many uses for this element commercially. On the other hand, rutherfordium has been used within the laboratory setting to conduct research. Most elements that are highly radioactive are used for nuclear power and medicinal purposes. 

Summary

Rutherfordium is a synthetic chemical element; it has symbol Rf and atomic number 104. It is named after physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be made in a particle accelerator. It is radioactive; the most stable known isotope, 267Rf, has a half-life of about 48 minutes.

In the periodic table, it is a d-block element and the second of the fourth-row transition elements. It is in period 7 and is a group 4 element. Chemistry experiments have confirmed that rutherfordium behaves as the heavier homolog to hafnium in group 4. The chemical properties of rutherfordium are characterized only partly. They compare well with the other group 4 elements, even though some calculations had indicated that the element might show significantly different properties due to relativistic effects.

In the 1960s, small amounts of rutherfordium were produced at Joint Institute for Nuclear Research in the Soviet Union and at Lawrence Berkeley National Laboratory in California. Priority of discovery and hence the name of the element was disputed between Soviet and American scientists, and it was not until 1997 that the International Union of Pure and Applied Chemistry (IUPAC) established rutherfordium as the official name of the element.

Details

Rutherfordium (Rf) is an artificially produced radioactive transuranium element in Group IVb of the periodic table, atomic number 104. Soviet scientists at the Joint Institute for Nuclear Research at Dubna, Russia, U.S.S.R., announced in 1964 the discovery of element 104, which they named kurchatovium, symbol Ku (for Igor Kurchatov, a Soviet nuclear physicist). In 1969, a group of American researchers at the Lawrence Radiation Laboratory of the University of California at Berkeley announced that they had identified isotopes of the element, different from the one identified by the Soviets; the Americans then proposed the name rutherfordium, in honour of the British physicist Ernest Rutherford.

In their experiment, the Soviets bombarded plutonium-242 with ions of neon-22, claiming to have obtained an isotope of element 104 that had a mass number of 260 and a half-life of 0.3 second. The Soviets then performed a series of chemical experiments with the isotope to demonstrate that it behaved in a manner that had been predicted for the element. When the workers at Dubna later used a more refined measuring technique, however, they found that the half-life of the isotope was 0.1 second, not 0.3 second as originally reported. This finding cast doubt on the chemical experiments with the element, because the results of those experiments could not have been obtained with atoms having a half-life of 0.1 second.

The American investigators did not follow the same procedure as the Dubna group, because the American equipment could not accelerate neon-22 ions to the necessary energies. Instead, they bombarded a target of californium-249 with ions of carbon-12 and carbon-13. Although unable to obtain the same isotope as the Soviet scientists, the Berkeley team did report positive identification of two, possibly three, isotopes of element 104. The bombardment of californium-249 with carbon-12 produced an isotope with a mass number of 257 and a half-life of 4–5 seconds; the carbon-13 bombardment produced an isotope with a mass number of 259 and a half-life of three to four seconds. The investigators at Berkeley subsequently, by bombarding curium-248 with oxygen-18, synthesized an isotope of element 104 that has a mass number of 261 and a half-life of 70 seconds.

Although the Soviets could make only a few atoms of their mass-260 isotope, the Berkeley group obtained thousands of the atoms having mass numbers of 257 and 259. Moreover, because the latter isotopes have longer half-lives, the Berkeley team was able to measure the energies of their emissions (alpha particles) and to detect their decay products (nobelium isotopes), thereby providing more extensive evidence of their discovery. The International Union of Pure and Applied Chemistry eventually ruled that element 104 be named rutherfordium.

Element Properties

atomic number  :  104
mass of most stable isotope  :  261.

Additional Information:

Appearance

A radioactive metal that does not occur naturally. Relatively few atoms have ever been made.

Uses

At present, it is only used in research.

Biological role

Rutherfordium has no known biological role.

Natural abundance

Rutherfordium is a transuranium element. It is created by bombarding californium-249 with carbon-12 nuclei.

Benzoic Acid

Gist

Benzoic acid is a white crystalline organic compound with the formula C7H6O2 that has various uses, including as a food and cosmetic preservative and in the production of ointments, insect repellents, and dyes. It is a simple aromatic carboxylic acid, naturally found in some plants, and is known for its antiseptic properties. While useful, benzoic acid is a skin and eye irritant, and its combination with vitamin C can form benzene, a known carcinogen. 

Benzoic acid is used as a preservative in food and drinks, an antifungal and antibacterial agent in medications and cosmetics, and a precursor for producing plastics and other chemicals. It's also found in products like toothpaste, insect repellents, and some cleaning supplies. 

Summary

Benzoic acid is a white, crystalline organic compound belonging to the family of carboxylic acids, widely used as a food preservative and in the manufacture of various cosmetics, dyes, plastics, and insect repellents.

First described in the 16th century, benzoic acid exists in many plants; it makes up about 20 percent of gum benzoin, a vegetable resin. It was first prepared synthetically about 1860 from compounds derived from coal tar. It is commercially manufactured by the chemical reaction of toluene (a hydrocarbon obtained from petroleum) with oxygen at temperatures around 200° C (about 400° F) in the presence of cobalt and manganese salts as catalysts. Pure benzoic acid melts at 122° C (252° F) and is very slightly soluble in water.

Among the derivatives of benzoic acid are sodium benzoate, a salt used as a food preservative; benzyl benzoate, an ester used as a miticide; and benzoyl peroxide, used in bleaching flour and in initiating chemical reactions for preparing certain plastics.

Details

Benzoic acid is a white or colorless crystalline organic compound with the formula C6H5COOH, whose structure consists of a benzene ring (C6H6) with a carboxyl (−C(=O)OH) substituent. The benzoyl group is often abbreviated "Bz" (not to be confused with "Bn," which is used for benzyl), thus benzoic acid is also denoted as BzOH, since the benzoyl group has the formula –C6H5CO. It is the simplest aromatic carboxylic acid. The name is derived from gum benzoin, which was for a long time its only source.

Benzoic acid occurs naturally in many plants and serves as an intermediate in the biosynthesis of many secondary metabolites. Salts of benzoic acid are used as food preservatives. Benzoic acid is an important precursor for the industrial synthesis of many other organic substances. The salts and esters of benzoic acid are known as benzoates.

Production:

Industrial Preparation

Benzoic acid is produced commercially by partial oxidation of toluene with oxygen. The process is catalyzed by cobalt or manganese naphthenates. The process uses abundant materials, and proceeds in high yield.

The first industrial process involved the reaction of benzotrichloride (trichloromethyl benzene) with calcium hydroxide in water, using iron or iron salts as catalyst. The resulting calcium benzoate is converted to benzoic acid with hydrochloric acid. The product contains significant amounts of chlorinated benzoic acid derivatives. For this reason, benzoic acid for human consumption was obtained by dry distillation of gum benzoin. Food-grade benzoic acid is now produced synthetically.

Laboratory synthesis

Benzoic acid is cheap and readily available, so the laboratory synthesis of benzoic acid is mainly practiced for its pedagogical value. It is a common undergraduate preparation.

Benzoic acid can be purified by recrystallization from water because of its high solubility in hot water and poor solubility in cold water. The avoidance of organic solvents for the recrystallization makes this experiment particularly safe. This process usually gives a yield of around 65%.

By hydrolysis

Like other nitriles and amides, benzonitrile and benzamide can be hydrolyzed to benzoic acid or its conjugate base in acid or basic conditions.

From Grignard reagent

Bromobenzene can be converted to benzoic acid by "carboxylation" of the intermediate phenylmagnesium bromide. This synthesis offers a convenient exercise for students to carry out a Grignard reaction, an important class of carbon–carbon bond forming reaction in organic chemistry.

Oxidation of benzyl compounds

Benzyl alcohol and benzyl chloride and virtually all benzyl derivatives are readily oxidized to benzoic acid.

Additional Information

Benzoic acid, the simplest benzene-based carboxylic acid, has been known since the 16th century. One of its discoverers was the legendary clairvoyant Nostradamus. Its most common natural source is gum benzoin, a resin found in the bark of trees of the genus Styrax.

Most benzoic acid produced today is synthetic. Its first industrial synthesis was the hydrolysis of benzotrichloride to calcium benzoate, followed by acidification. This method has been completely displaced by the air oxidation of toluene, which avoids the problem of product contamination with chlorinated byproducts.

Many processed foods contain benzoic acid or one of its salts as a preservative. The acid inhibits the growth of bacteria, molds, and yeasts; it works best when the food has an acidic pH value. Benzoic acid also is often found in topical antifungal preparations.

I made an account just to tell this joke.
Aren't you going to give me an apple-ause?
* * *
Q: What do you call an apple that's been around the world?
A: Johnny Appleseed.
* * *
Q: What did the apple say to the almond?
A: You're Nuts!
* * *
Q: What did one maggot say to the other who was stuck in an apple?
A: Worm your way out of that one, then!
* * *
Q: What lives in apples and is an avid reader?
A: A bookworm !
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