Category Physics

How are Computer chips made?

A chip is a tiny piece of silicon containing several simple electronic circuits. It is also called an integrated circuit or IC. For making a chip, only single-crystal pure silicon is used as its atoms are uniformly bonded and hence accepts any electrical pattern imposed on it. A single-crystal cylinder is sliced into thin wafers of about 0.05 cm thickness each.

            Pathways of electricity are then engraved onto this wafer using certain chemicals or ultraviolet light. The wafer is subsequently cut into small chips each of which is mounted on a ceramic base and bound with gold wire.

 

How do Spacesuits protect?

A spacesuit is protective gear that protects an astronaut from the hostile environment of extremely low pressure, low temperature and radiation in space. It is made up of several layers of strong synthetic materials including Teflon and nylon which shield the astronauts from tiny particles called micrometeoroids. The intense solar radiation is reflected by a white plastic layer which has a metallic coating.

The interior of the suit is pressurized but for which the astronaut’s blood would boil off in the vacuum of space.

A backpack carries water both for drinking as well as to keep the astronaut cool. Water flows through pipes in the astronaut’s suit and carries away body heat.

The spacesuit also carries a two-way communication system to enable the astronaut communicate in the vacuum of space.

How do Fireworks display colours?

The brilliant white, sparkling yellow, glowing red and the shimmering blue colours in the fireworks that brighten up a Diwali evening are produced by metals or metal salts present in the fireworks. Metals have the property of emitting light of a particular colour while they burn. For instance, when sodium or its salts burn, yellow light is given out. Similarly, on burning, finely divided aluminium gives out bright white light. Strontium salts give out red colour while copper and barium salts produce intense blue and green colours respectively. Fireworks manufacturers make use of this property of metals and their salts and use them in various combinations in crackers to produce spectacular fireworks display. 

How does Shampoo Produce lather?

Lather or foam is nothing but a collection of tiny soap bubbles. There is always a large quantity of air trapped between the hair strands on our head.

Shampoo is made of mild soap-like material with high solubility in water. When shampoo is rubbed on the hair with water, thin soap films are formed which during rubbing traps the air present between the hair strands to form small bubbles. As there are thousands of hair strands on the scalp, copious lather is produced.

 

How do Metals corrode?

The corrosion of metals is caused by chemical reaction. Water, salts, acids and gases — all can react with metals and over time corrode it. Iron, for example, combines readily with the oxygen in air in the presence of moisture to form red iron oxide, we call rust. Copper as bronze corrodes in presence of acids or sulphur dioxide in air forming a greenish coating of copper salts called patina, Metals can also corrode due to electrochemical reaction if two dissimilar metals such as steel and copper are Joined together and exposed to water. Here one of the metals gives up electrons and gets corroded in the process. 

 

Is rain water hundred per cent pure? Can we use it as drinking water?

    All the natural water contains dissolved ions (positive valency anions and negative valency captions) within them.

            Rain water which is formed due to natural distillation process (i.e.) evaporation, condensation and precipitation. It is supposed to be in a very dilute solution with very less dissolved solids generally between 10-20mg/lit.

            All the dissolved ions present in them are in the range of 1-3 mg/lit. So it is considered to be pure and useful for drinking purposes. Moreover their PH is between 6.7 and 7.2.for consumption purposes. But the concentration varies from region to region.

            Near the coastal area due to sea spray the ions is higher, if more suspended particles in the air, they react with water molecules to give more dissolved ions.

            If the air is full of Carbon dioxide, Nitrogen dioxide and Sulphur dioxide, then they all dissolve in water to form an acid rain, which will cause more harm to vegetation an its PH is reduced.

            Pure rain water does not contain enough dissolved minerals and ions needed for the body. So after suitable modification and alteration the rain water can be used for consumption.