A Sci/Tech "Common Bond" Quiz

Answer: Arcturus

Spica appears bluish, Polaris white, the Sun yellow and Arcturus orange.

Blue stars are the hottest, having surface temperatures of between 10,000 K and 50,000 K. Next are the white stars, which are between 7,500 K and 10,000 K at the surface. The Pole Star, Polaris, is an example of a white star. Cooler than the blue and white stars are the yellow stars, such as our Sun, which have surface temperatures of 5,000 K to 7,500 K. Red and orange stars are the coolest (and when I say "coolest", I mean having surface temperatures of 2,500 K to 5,000 K) stars that our eyes are capable of seeing, and thus Arcturus is the coolest of the four stars. Beyond these are stars that are so cool they emit light only in infrared or radio wavelengths, making them impossible for the human eye to detect.

You might have seen a piece of iron being heated - after being heated a certain amount it becomes red-hot, and eventually glows white. If heated even further, it would glow blue. Another apt analogy is that of the flame of a candle: the inner blue region is the hottest, the intermediate yellow region is moderately hot, and the outer orange region is the coolest.

Answer: Sour

All acids, when dissolved in water, taste sour. In fact, acids are the ONLY substances that taste sour. For example, vinegar is a dilute solution (3 - 5%) of acetic acid. Other edible acids include citric acid, found in citrus fruits like lemons and limes, and tartaric acid, found in tamarinds. On the other hand, alkalis - aqueous solutions of bases - taste bitter.

Answer: A ball

For a given volume, a sphere has the least surface area (and contrarily: for a given surface area, a sphere has the maximum volume), and so a ball would be the preferred shape for the blacksmith to mould his iron into. Ever wondered why soap-bubbles are usually spherical in shape? It's for this very reason, because of which surface tension causes the bubble to be spherical.

This shape of a bubble can easily be distorted by air currents, including your breath!

Answer: Blood

Based on the presence of certain substances ("antigens" and "antibodies", for the initiated) in the red blood cells and blood plasma of a person, blood can be grouped into 8 main types. The average prevalence of each of these types in a typical human population is: O+ 38%, A+ 34%, B+ 9%, O- 7%, A- 6%, AB+ 3%, B- 2% and AB- 1%; i.e., O+ is the most common (38% of the population) and AB- is the least (about 1%). People whose blood-type is O- are called universal donors because their blood won't be rejected by any recipient, regardless of his/her blood-type. On the other hand, those with blood-type AB+ are called universal recipients; they can accept blood from people of all blood groups.

("Erythrocyte" and "leucocyte" are respectively medical lingo for "red blood cells" and "white blood cells"; platelets are fragments of dead blood cells, involved in the clotting of blood.)

Answer: Citric acid (2-Hydroxy-1,2,3-propanetricarboxylic acid)

In Scotland and other places, citric acid is a used as a buffer to lower the pH of a solution and thus increase the solubility of street heroin, which is why pharmacies in the UK control the sale of citric acid. Citric acid is naturally present in all life-forms, and excess quantities can be easily eliminated from the system. Citric acid is used as a preservative and flavouring agent in foods - especially in aerated beverages, to which it lends a sour taste - and as a buffer to control the pH of household cleaners and medicines.

Answer: Tree

The General Sherman Tree is a Giant Sequoia (Sequoiadendron giganteum) and is the largest in the world - the volume of its trunk is 1487 cubic metres. (And this is as of 2002; each year, it adds enough wood to make another 30 metre tall and 30 centimetre wide tree!) The total mass of General Sherman has been estimated at ten times that of a typical blue whale.

The tree is located in the Sequoia National Park, in the southern Sierra Nevada in California, USA. Though the Giant Sequoias are the *largest* trees in the world, the *tallest* ones are the Coast Redwood trees, of which there are at least 15 trees more than 110 metres (361 feet) tall.

Answer: Honey

Liquid honey, containing up to 18% moisture, does not spoil; virtually no organism can multiply to a significant extent in it. This is because of its sugar content, which kills bacteria by "osmotically lysing" them - the high concentration of sugar causes water to move into the bacterium across its cell membrane, until it is so full of water that it explodes! Honey is hence also used as a disinfectant.

Honey can be extremely dangerous for infants - when mixed with the non-acidic digestive juices of a baby's stomach, it provides the ideal environment for botulinum spores to grow. These bacteria, one of the few that survive in honey, release toxins that can sicken or even kill the baby. These spores, however, are harmless to adults, because the acidic medium of an adult stomach destroys them.

Answer: Dichromate ions

Redox (reduction - oxidation) reactions are the most fundamental reactions of chemistry. Both the processes of reduction (the gain of electrons) and oxidation (the loss of electrons) are complementary. While dichromate ions are good oxidising agents, nascent hydrogen and carbon are reducing agents. In general, most metals (especially alkali metals like sodium, potassium, etc.) are reducing agents and non-metals (especially halogens like fluorine, chlorine, iodine, etc.) are oxidising agents.

Most energy in biological systems is stored and released by means of redox processes: in photosynthesis, atmospheric carbon dioxide is reduced to sugars like glucose and water is oxidised to molecular oxygen; respiration, on the other hand, involves the oxidation of sugar to produce carbon dioxide and water.

Answer: Vitamin C

Scurvy is a disease characterised by general weakness, joint pains, black and blue marks on the skin and bleeding gums. It is believed to have been discovered by Hippocrates of Cos (460 BC - 377 BC), a physician in ancient Greece. Crusaders in the 13th century AD suffered from the disease in large numbers, leading to the loss of a large number of lives.

It was a major problem faced by sailors on long sea voyages, and was also responsible for many deaths during World War I. James Cook (1728 - 1779), the British explorer and navigator, remarkably lost none of his crew to scurvy during his First Pacific Voyage, something quite un-heard of in the 18th century! He forced his men to eat citrus fruits and sauerkraut (finely-sliced white cabbage fermented by the bacteria lactobacillus, the same bacteria responsible for the formation of yogurt), at the risk of being flogged if they did not follow the instructions.

However, it wasn't understood *how* exactly these foods prevented scurvy, until vitamin C was discovered and isolated.

Answer: orange

Here's how each of the previous answers is connected to the word "orange":

Q1: ARCTURUS- the star Arcturus is distinctly orange in colour. This star, the fourth-brightest in the night sky, shines all night in spring in the northern hemisphere and autumn in the southern hemisphere.
Q2: SOUR- Most oranges taste sour, a result of the slight acidity of the orange's juice.
Q3: A BALL- The shape of an orange is more or less spherical or like a ball.
Q4: BLOOD- Blood oranges are a kind of orange that get their name from their crimson-red interior and peel. The juice of a blood orange is also red in colour.
Q5: CITRIC ACID- Oranges contain a large amount of citric acid, which gives them their sour taste. In fact, all fruits of the genus Citrus, such as lemons, grapefruits, limes and tangerines, are sour due to the presence of citric acid.
Q6: TREE- Oranges grow on trees that can be as tall as 10 metres, with evergreen leaves that are 4-10 centimetres long and thorny shoots.
Q7: HONEY- Orange blossom honey is a highly prized type of honey, which has a distinct orange-like flavour. It is produced by putting beehives in groves of orange trees while the flowers are in bloom. The nectar extracted by the bees from the orange blossoms is made into honey by them. This also helps pollinate varieties of orange that require seeds for propagation.
Q8: DICHROMATE IONS- A solution of dichromate ions in water is bright orange in colour (depending on the degree of concentration of the ions). This, unfortunately, is one of the few brightly coloured solutions that one comes across in a chemical laboratory; don't believe those cartoons that show multitudes of test-tubes containing jazzy and colourful bubbling liquids!
Q9: VITAMIN C- All citrus fruits, including oranges, are particularly rich in vitamin C, besides a host of other nutrients.

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