ANODE RAYS AND DISCOVERY OF PROTONS

ANODE RAYS AND DISCOVERY OF PROTONS



The existence of positively charged particle in an atom was shown by GOLDSTEIN in 1886. He repeated the discharge tube experiments by using a perforated cathode. On applying a high voltage at low pressure, Goldstein observed a new type of rays emerging from the holes in the cathode. These rays traveled in a  direction opposite to that of the cathode rays. These rays were called ANODE RAYS, CANAL RAYS or POSITIVE RAYS.

The charge to mass ratio (e/m) of the particles in the anode rays was found to depend upon the nature of the gas in the discharge tube. The e/m value was found to be maximum when hydrogen gas was taken in the discharge tube. This means that the positive particles formed hydrogen are the lightest. These lightest positively charges particles were named  PROTONS.

The charge on this particle has been found to be equal in magnitude but opposite in sign of that of electron, 

DISCOVERY OF THE ELECTRON - CATHODE RAYS AND PROPERTIES OF CATHODE RAYS

DISCOVERY OF THE ELECTRON - CATHODE RAYS



The electron was discovered as a result of the study of conduction of electricity through gases at low pressures. The experiments were conducted in discharge tubes. When a high potential is applied to a gas taken in a discharge tube at very low pressure, certain rays are emitted from the cathode. These rays are called CATHODE RAYS


PROPERTIES OF CATHODE RAYS


From the various experiments carried out by J.J Thomson  and others, the cathode rays have been found to possess the following properties.

1. They start from cathode and move towards the anode in straight lines.
2. Cathode rays consist of material particles.
3. When an electric field is applied to a stream of cathode rays, they get deflected  towards the positive plate of the electric field. This shows that the particles in the cathode rays carry negative charge.
4. Cathode rays are deflected by magnetic fields in a direction expected for negative particles.
5. Cathode rays produce X-rays when they strike against the surface of hard metals like tungsten, copper etc.
6. Materials coated with fluorescent or phosphorescent substances produce glow when hit by cathode rays.

                       All these observations led to the conclusion that cathode rays consist of fast moving negatively charged particles. These particles were named ELECTRONS.

CALLIGRAPHY

 C a L L i G r A P h Y

      CALLIGRAPHY IS BEAUTIFULLY FORMED LETTERING. The term applies to written text and illumination ( the decoration of manuscripts using gold leaf and colour). The essential materials needed to practice  calligraphy are a writing tool, ink and a writing surface. Quills are among the oldest writing tools. They are usually made from goose or turkey feathers and are noted for their flexibility and ability to produce fine lines. A quill point, how ever is not very durable and constant re cutting and trimming   is required. The most  commonly used writing instrument in western calligraphy is a detachable, metal nib held in a pen holder. The metal nib is very durable, and there are wide range of different types. Particular types of nibs- such as copper plate, speed ball and round hand nibs-are used for specific styles of lettering. Some nib has internal ink reservoirs and others have reservoirs that are detachable. Brushes are also used for writing  and for filling in outlined letters and painting decoration. Other writing tools used in calligraphy are fountain pens, felt-tip pens, rot ring pens and reed pens. Calligraphy inks may come in liquid form, or as a solid ink stick. Ink sticks are ground down in distilled water to form a liquid ink. The most common writing surface for calligraph are good quality, smooth surfaced papers. To achieve the best writing position, the calligrapher places the paper on a drawing board set at an angle.    

           

ASTEROIDS, COMETS, AND METEOROIDS

ASTEROIDS, COMETS, AND METEOROIDS 

ASTEROIDS, COMETS, AND METEOROIDS  are all debris remaining from the nebula in which the solar system formed 4.6 billion years ago. Asteroids are rocky bodies up to about 1,000 km in diameter, although most are smaller. Most  of them orbit the sun in the asteroid belt, which lies between the orbits of mars and Jupiter. Comets may originate in a huge cloud (called the Oort cloud) that is thought to surround the solar system. They are made of frozen gases and dust, and are a few km in diameter. Occasionally, a comet is deflected from the Oort cloud to the orbit the sun in a long, elliptical path. As the comet approaches the sun, the comet's surface starts to vaporize  in the heat, producing  a  brightly shining coma (a huge sphere of gas and dust around the nucleus ), a gas tail, and a dust tail. Meteoroids are small chunks of stone or stone and iron, some of which  are fragments of asteroids  or comets. Meteoroids range in size from tiny dust particles to objects tens of meters across. If a meteoroid enters the Earth's atmosphere, it is heated by friction and appears as glowing streak of light called a meteor ( also known as a shooting star). Meteor showers occur when the Earth passes through the trail  of dust particles left by a comet. Most meteors burn up in the atmosphere. The few that are large enough to reach the Earth's surface are termed meteorites.  

CHEMICAL REACTIONS

CHEMICAL REACTIONS



A CHEMICAL REACTION TAKES PLACE whenever bonds between atoms are broken or made. In each case atoms or groups of atoms are rearranged, making new substances (products) from the original ones (reactants). Reactions happen naturally, or can be made to happen; they may take years or only a instant. Some of the main types are shown here. A reactions   usually involves a change in energy. In a burning reaction, for example, the  making of new bonds between atom releases energy heat and light. This type of reaction, in which heat is given off, is an exothermic reaction. Many reactions, like burning are irreversible, but in some cases the reactions are reversible (reaction in either directions). Reactions can be used to form solids from solutions; in a double decomposition reaction two compounds in solution break down and re-form into two new substance,often creating a precipitate (insoluble solid); in displacement an element (eg.copper) displace another element (eg. silver) from a solution. The rate  (speed) of a reaction is determined by the shape of the reactants. To describe and keep track of reactions, internationally recognized chemical symbols and equations are used. Reactions are also used in laboratory to identify matter. An experiment with candle wax, for example demonstrates that it contains carbon and hydrogen.

KOOKABURRA BIRD (habit)

KoOkAbURrA BirD

The Kookaburra's rolling, laughing call is one of the best known-sounds in the animal World. The birds raise a wild chorus of crazy laughter as they go to roost in the tree tops at dusk, and again wake everyone with in hearing just as dawn breaks, so regularly that in the hinter lands of Australia they are known as the "bushman's clock". Australians value the Kookaburra, not only as an intriguing member of the strange fauna, but for its habit of feeding on snakes and lizards. The Kookaburra seizes snakes behind the head and kills them by dropping them from a height, or else carries them to a perch and batters them senseless with its big bill before swallowing them. Less welcome is the Kookaburra's fondness for the young of other birds, and its occasional raids on farmyards for ducklings and baby chicks. In the wild, Kookaburra  are known to be partial to be young of other birds and snakes, as well as insects and small reptiles. In the zoo they are fed commercially prepared bird of prey mix and dead baby chicks. Kookaburras generally live in pairs or in small groups in open woodland. The incubate their two or four pure white eggs in hollow tree trunks, tree holes or in excavated termite nests. Both adults incubate for a period of 25 days. The young leave the next 30 days after hatching, but the parents continue to fees them for another 40 days.

AIR

A i R

The air we breathe has seventeen different gases. It is made up mostly of nitrogen, not Oxygen. Recently, human activities have changed the balance in the Earth's atmosphere. Atmosphere is the air that surrounds the  Earth. The wide spread burning of coal and oil increases the levels of carbon monoxide gas. Scientists believe this air pollution may cause Global warming. Certain chemicals used in the air conditioners, farming and manufacturing are the problem. They break down the ozone layer around the Earth. With less protection from the sun the air temperature rises and makes the Earth warmer. This leads to harmful effects on people, farming, animals and the natural environment.

WHAT IS MEANT BY A YEAR AND A LEAP YEAR..?

YEAR AND LEAP YEAR

The Earth takes a year to orbit the sun. it is about 365 days. The exact time is 365.242199 days. To make years come out even, every four years there is a leap year. It has 366 days. The months on the calender are based on the phases of the moon. The Greeks has a 10 month calender. About 60 days were left over. So the Romans added two months. The idea of seven day weeks come from the HOLY BIBLE. The  Romans named the days. We still use three of these names: Sunday ( Sun day), Monday (Moon day) ans Saturday ( Saturn day).

JACK FRUIT GREW IN MY BEAUTIFUL VILLAGE CHETTIKULAM

This post views the tasty sweet fruit grew in our beautiful village CHETTIKULAM .The name of this fruit is JACK FRUIT , in Malayalam we call it as "CHAKKA" Its really a tasty fruit. Even the kids to old age people like this fruit. When this fruit gets  ripen even the birds and squirrel came to eat it. It is also used to make curry. Its really a tasty fruit. 

FOSSILS

F o S s i L s

THE FOSSILS ARE THE REMAINS of plants and animals that have been preserved in rock. A fossil may be the preserved remains of an organism itself, an impression of it in rock , or preserved traces (known as trace fossils) left by an organism while it was alive, such as organic carbon outlines, fossilized footprints or droppings. Most dead organisms soon rot away or are eaten by scavengers. For fossilization to occur, rapid burial by sediment is necessary. The organism decays, but the harder parts-bones,teeth and shells foe example-may be preserved and hardened by minerals from the surrounding sediment. Fossilization may also occur even when  the hard parts of an organism are dissolved away to leave am impression called a mould. The mould is filled by minerals, there by creating a cast of the organism. The study of fossils (palaeontology) can not only show how living things have evolved, but can also help to reveal the Earth,s geological history-for example , by aiding in the dating of rock strata. 

GALAXIES

G a L A X i e S

A GALAXY IS A HUGE MASS OF STARS, nebulae, and interstellar material. The smallest galaxies contain about 100,000 stars, while the largest contain up to 3,000 billion stars. There are three main types of galaxy, classified according  to their shape: elliptical, which are oval shaped; spiral, which have arms spiraling outwards from a central bulge; and irregular, which have no obvious shape. Sometimes, the shape of a galaxy is distorted by a collision with another galaxy. Quasars (quasi-stellar objects) are thought to be galactic nuclei but are so far away that their exact nature is still uncertain . They  are compact, highly luminous objects in the outer reaches of the  known Universe; while the furthest known "ordinary"  galaxies are about 10 billion light years away, the furthest known quasar is about 15 billion light years away. Active galaxies, such as Seyfert galaxies and radio galaxies, emit intense radiation. In a Seyfert galaxy, this radiation comes from the galactic nucleus; in the ratio galaxy, it also comes from huge lobes on either side of the galaxy. The radiation from active galaxies and quasars is thought to be caused by black holes

THE MILKY WAY

ThE MiLKy WaY

THE MILKY WAY IS THE NAME GIVEN TO THE FAINT BAND OF LIGHT that stretches  across the night sky. This light comes from the stars and nebulae in our galaxy, known as the MILKY WAY Galaxy as "the galaxy". The galaxy is shaped like a spiral, with a dense central bulge that is encircled by four arms spiralling  outwards and surrounded by a less dense halo. We can not see the spiral shape because the solar system is in one of the spiral arms, the orion arm ( also called the Local arm ). From our position, the  center of galaxy is completely obscured by dust clouds; as a result, optical maps give only a limited view of galaxy .  However, a more complete picture be obtained  by studying radio, infra-red and other radiations. the central bulge of the galaxy is a relatively small, dense sphere that contains mainly older red and yellow stars. The halo is a less dense region in which the oldest stars are situated; some of these stars may be old as the Galaxy itself ( possibly 15 billion years). The spiral arm contains mainly hot, young, blue stars as well as nebulae (clouds of dust and gas inside which stars are born). The Galaxy is vast, about 100,000 light year across ( a light year is about 9,460 billion km); in comparison, the solar systems seems small st about 12 light hours across ( about 13 billion km). the entire Galaxy is rotating in space, although the inner stars travel faster than those further out. The sun, which is about two-thirds out from the center, completes one lap of the Galaxy about every 220 million years.

ENERGY

E n e R G y

ANYTHING THAT HAPPENS- from a pin drop to an explosion-requires energy. Energy is the capacity for "doing work" (making something happen). Various forms of energy exists  including light, heat, sound, electrical, chemical, nuclear, kinetic and  potential energies. The  law of conservation of energy states that the total amount of  energy in the universe is fixed- energy cannot be created or destroyed. In means the energy can only change from one form to  another ( energy transfer). For example, potential energy is the energy that "stored" , and can be used in the future. An object gains potential energy when it is lifted; as the objected is released, potential energy changes into  the energy of motion (kinetic energy). during  transference, some of the energy converted into heat. A combined heat and power station can put some of the otherwise "waste" heat to useful effects in local schools and housing. Most of the Earth's  energy is provided by the sun, in the form of electromagnetic radiation. Some of this energy transfers to plant and animal life, and ultimately to fossil fuels, where it is stored in chemical form. Our bodies obtain energy from food we eat, while energy needed for other tasks also, such as heating and transport, can be obtained by burning fossil fuels-or by harnessing natural forces like wind or moving water- to generate electricity. Another source is nuclear power, where energy is released by reactions in the nucleus of an atom. All energy is measured by the international unit, the joule ( J ) . As a guide, one joule is about equal to the amount of energy needed to lift an apple one metre.

ELeCtRiCitY AnD MagNETisM

ELECTRICITY AND MAGNETISM

ELECTRICAL EFFECTS result from an imbalance of electrical charge, There are two types of electrical charge ,named positive (carried by protons) and negative (carried by electrons). If charges are opposite (unlike), they attract one another, while like charges repel. Forces of attraction and repulsion (electrostatic forces) exist between any two charges particles. Matter is normally uncharged, but if electrons are gained, an object will gain an overall negative charge; if they are removed, it becomes positive. Objects with an over all negative or positive charge are said to have an imbalance of charge, and exerts the same forces as individual negative and positive   charges. On this larger scale, the forces will always act to regain the balance of charge. This causes static electricity.  For example, lightning is produced by clouds discharging a huge excess of negative electrons. If charges are "free"-in a wire or material that allows electrons to pass through it - the forces cause a flow of charge called an electric current. Some substances exhibit the strange phenomenon of magnetism-which also produces attractive and repulsive forces. Magnetic substances consist of small regions called domains. Normally unmagnetized, they can be  magnetized by being placed in magnetic field. Magnetism and electricity are inextricably linked, a fact put to use in motors and generators. 

RESISTANCE: For a given voltage, the flow of current depends upon the resistance of a circuit. Resistance is the degree to which a substance resists electrical current. It is measured in ohms.

Electric motor: In a motor, magnetic forces between the winding and permanent produced a rotatory motion.

                      

Electric generator: In a generator, the rotor  rotates within the magnetic field of the stator to produce an electric current.