Science

Here are all important topics and notes to be covered

We have given all important topics and their notes in very short and in a simple way, We have added some pictures related to the topics, That will help you to easy to understand what is that topic exactly, And it will very easy to learn.

Topics

Distance

Distance is the actual path.

Distance is always positive.

Distance has only magnitude.

Distance is more than or equal to Displacement ( Always )

Displacement

Displacement is the shortest distance.

Displacement may be positive, negative, or zero.

Displacement had magnitude as well as direction.

Displacement is less than or equal to Distance

Speed

Speed is the distance traveled by a body in unit time.

Speed is a scalar quantity.

Speed=distance

time

Speed is always positive or zero but never negative.

Velocity

Velocity is the distance traveled by the body in a given direction in unit time.

velocity is a vector quantity.

It may be positive, negative or zero.

Velocity=Displacement

Time

Force

It is measured in Newton ( N ) or dyne

Force=mass.acceleration

Acceleration

The rate of change of velocity is called acceleration.

Acceleration=change in velocity

Time

a=(v-u)

Work

Work is said to be done when a force applied to an object cause displacement of the object.

Work=force.displacement

Energy

The capicity to do work is called energy.

Law of conservation of energy

Energy can neither be created nor destroyed, it can be converted from one form into another. Thus the total amount of energy in the universe remains constant.

Free Fall

An object falling freely under the influence of the force of gravity is said to be free fall or to be falling freely.

An object is moving under the influence of the force of gravity alone is called free fall.

Power

Power is the rate of doing work.

Power=Work P=W

Time T

The SI unit of work is the joule.

Electric current

An electric current is the flow of electrons through a conductor.

I= Q

The SI unit of electric current is Ampere.

1 Ampere=1 coulomb

1 Second

Mirror

The surface which reflects light and which creates a clear image is called a mirror.

The image formed by a plane mirror is of the same size as the source

To see a full image of a person standing in front of a mirror the minimum height of the mirror must be half of the height of a person.

Longitudinal Waves

The particle of the medium oscillate about their central or mean position, in a direction parallel to the propagation of the wave, such waves are called longitude waves.

Transverse wave

The wave was created by dropping a stone in still water. the particle of water oscillates up and down. This oscillation are perpendicular to the direction of propagation of the wave such waves called a transverse wave.

Echo

An echo is the repetition of the original sound because of reflection by some surface.

At 22 degrees Celcius the speed of sound in air is 344m/s for different temperatures the distance is different.

The Golghumat at Vijapur in Karnataka is an excellent example of echo.

SONAR

Sound Navigation and Ranging

Ultrasonic sound is used here.

SONAR is used to determine the depth of the sea to search underwater hills, valleys, submarines, icebergs, sunken ships, etc.

Occurrences of carbon

The name "Carbon" is derived from the Latin word "carbo" meaning coal.

Carbon is in found n nature in the free as well as the compound state.

Carbon in the free state is found as diamond and graphite.

Diamond

Diamond is found in India mainly in Govalkonda (Karnataka) and pannaPanna (Madhya Pradesh).

Diamonds are also found in southern Africa, Brazil, Belgium, Russia, and America.

The density of the diamond is 3.5g/cm cube.

Carbon Diaoxide

molecular formula = co2

Molecular Mass = 44

melting point = -56.6 degree Celsius.

Carbon Dioxide occurs in the air in the free state to extent of about 0.03%.

liquified Co2 is used to remove caffeine from coffee.

Non-crystalline/Amorphous forms

Coal

Peat.
Lignite.
Bituminous coal.
Anthracite.

Charcoal.

Newton's universal law of Gravitation

Every object in the universe attracts every object with a force which directly proportional to the product of their masses and inversely proportional to the square of distance between them.

Mass

mass is the amount of matter present in the object.

mass is the same everywhere.

mass is a scalar quantity.

The SI unit of mass is Kg.

Weight

weight depends upon the gravitational dependence on the force of the planet.

weight is changed by the planet.

weight is a vector quantity.

The SI unit of weight is Newton.

Escape velocity

The initial velocity of an object due to the object overcoming the gravitation a pull by the earth that initial velocity is called escape velocity.

V esc of earth = 11.2 km/s

V esc of moon = 2.37 km/s

Displacement Reaction

The reaction in which more reactive ions and make a compound that reaction called displacement reaction.

CuSo4 + Fe = FeSo4 + Cu

Double Displacement Reaction

The reaction in which the exchange of ions occurs and the precipitate has formed that type of reaction called double displacement reaction.

AgNo3 + NaCl = AgCl + NaNo3

Exothermic Reaction

The reaction in which heat is liberatd that reaction is called exothermic reation.

CaO + H2O = Ca(OH)2 + heat

Endothermic reaction

The reaction in which heat is absorbed is called an endothermic reaction.

CaO + heat = CaO + Co2

Combination Reaction

When two or more reactants combine in a reaction to form a single product, it is called a combination reaction.

2 Mg + O2 = 2 MgO

Decomposition reaction

The chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction.

2 H2O = 2H2 +O2

Rancidity

When oil or fat or leftover cooking oil for making foodstuff undergoes oxidation if stored for a long time and it is found to have a foul odor called rancidity.

Heating effect of electric current

When an electron flows from the conductor then that electron is collides on the particle of that conductor which is stationery and which has potential energy then that potential energy is converted into heat energy is called the heating effects of electric current

Joule's law

H = ( I x I ) R x t

The heat generated in conductors is directly proportional to the product of

a) square of electric current

b) Resistance

c) Time of energy provide

is called Joule's law

Magnetic effect of electric current

When more amount of electric current is flowing through the conductor then magnetism is produced around the conductor.

magnetism effect is discovered by sir Hans Christain oersrted.

magnetism produced around the conductor has direction and is circular.

Electric motor

A device changing electrical energy into mechanical energy is known as an electric motor.

latent heat

The heat energy required to change a substance from one state to another at that constant temperature is called as latent heat of a substance.

Regelation

The phenomenon in which the ice converts to liquid due to applied pressure and then re-converted to ice once the pressure is removed is called regelation.

dew point tempreture

If the temperature of unsaturated air is decreased, a temperature is reached at which the air becomes saturated with water vapor. this temperature is called dew point temperature.

Newtons laws of motion

First law

An object continues to remain at rest or in a state of uniform motion along a straight line unless an external unbalanced force acts on it.

Second law

The rate of change of momentum is proportional to the applied force and the change of momentum occurs in the direction of the force.

Third law

Every action force has n equal and opposite reaction force that acts simultaneously.

About scientists

The Italian scientist Alessandro Volta constructed the first cell. (electric cell

German physicist, George Simon ohm established a law for measuring the resistance of a conductor.

in his honor, the unit of resistance is called ohm.

In 1883 Eichler, a botanist, classified the kingdom Plantae into tow sub-kingdom

1. cryptogams

2. phanerogams.

The Italian physicists Borelli and Vivani in the 1660s, first calculated the speed of sound.

The first person to step on the moon (1969) was Neil Armstrong (USA)

The first artificial satellite sputnik was sent by the soviet union is (1957).

In 1886 Johann Gregar Mendel discovered Heredity.

In1901 Huge de Vries discovered mutational Theory ( Sudden Change )

In 1992 Walter and Sutton observe the cell of the grasshopper and discovered the chromosomes

in 1944 Ostwald Avery, mclyn macarthy, Colin Macleod expect various living organisms to hare DNA as genetic material.

In 1961 franciou Jacob jack monad proposed the model for the process of protensysnteisis.

The German chemist Wohler synthesized organic compound urea from an inorganic compound ammonium cyanate.

kingdom monera, protests and fungi of five kingdom classification system proposed by Robert Wittaker (1959)

Components of DNA Molecule.

Ribose sugar
Nitrogen bases
phosphate molecule.

Sound

The limit of hearing of the human ear are 20Hz to 20,000Hz. This sound is called audible sound.

our ear cannot hear the sound of frequencies lower than 20Hz and higher than 20,000Hz (20KHz).

Sound with a frequency smaller than 20Hz is called infrasound

The sound produced by a pendulum and the sound generated by the vibration of the earth's crust just before an earthquake is an example of such sound (Infra).

Sound waves with frequency 20,000Hz 920KHz) are called ultrasonic sounds.

Uses Of Ultrasonic sound

For communication between ships at sea.

to join plastic surfaces together -to sterilize liquids like milk by killing the bacteria in it so that the milk keeps for a longer duration.

sonography technology.

X-ray.

In industry, to clean intricate parts of machines where hands cannot reach.

To locate the cracks and faults in metals blocks.

Refraction of light

light changes its direction when going from one transparent medium to another transparent medium this is called the refraction of light.

Laws of Refraction

When Raya of light passes from a rarer medium to the denser medium it bends towards the normal.

When a ray of light passes from a denser medium to a rarer medium it bends away from the normal.

When a light ray is an incident normally at the boundary between two media, it does not change its direction and hence does not get refracted.

Reactivity series of metal

Potassium
Sodium
Lithium
Calcium

Magnesium
aluminum
Zinc
Iron
Tin
Lead

Copper
Mercury
Silver

Gold

Graphite

Graphite is found in natural states in Russia, New Zealand, America, and India.

The lead used in pencil is made by mixing graphite with clay.

This process was discovered by Nicholas Jacques Conte in 1795.

Graphite found in nature is black, soft, brittle, and slippery.

Due to layered structure graphite can be used for writing on paper.

The density of graphite is 1.9 to 2.3g/cm cube.

used for making lubricants.

making carbon electrodes.

paints and polish.

used in arc laps which gives a very bright light.

Uses of Diamond

Glass cutting.

Rock drilling machines.

Ornaments.

diamond knives are used in eyes surgery.

Diamond dust is used to polish other diamonds.

To make windows give protection from radiation in space and artificial satellites.

India was famous for the "Kohinoor" diamond. This diamond was found in the 13th century in the mine at Gunter (Andra Pradesh). Its weight was 186 carats.

Specific heat capacity

The amount of heat energy required to raise the temperature of a unit mass of an object by 1-degree Celcius the is called specific heat capacity of that object

the unit of heat

mks = joule

cgs = calorie

heat energy lost by a hot object = heat energy gained by a cold object

is called the principle of heat exchange

Factors affecting the rate of a chemical reaction

Nature of a Reactant.

Size of the particles of reactant.

the concentration of reactant.

the temperature of the reaction

catalyst.

the substance in whose presence changes without causing any chemical change to it is called a catalyst.

Oxidation and Reduction

The chemical reaction in which a reactant combines with oxygen or loses hydrogen to form the product is called an oxidation reaction.

When the positive charge on an atom or an ion increases or the negative charge on them decreases it is called oxidation.

When the positive charge decreases or the negative charge increases is called reduction.

Corrosion

A certain type of reddish-colored solid layer collects on their metallic surface this layer is called rust.

Its chemical formula is Fe2O3 x H2O

The slow process of decay or oxidation of metals due to various components of the atmosphere is known as corrosion. Iron rusts and a reddish colored layer collected on it this is corrosion of Iron.

Salt

The ionic compound which does not contain H+ and OH- ions and contains only one kind of cation and anion is called simple salt.

About 80 million tons of salts are added every year to seawater.

common salts is a colorless and crystalline ionic compound

the 25% aqueous solution of salt is called saturated brine.

The important salts found in seawater.

1.sodium chloride - NaCl
2.magnesium chloride -MgCl2
3.Magnesuum sulphate - MgSo4
4.otassium chloride - KCl
5.Calcium carbonate - CaCo3
6.Magnesium bromide - MgBr2

Salt is also obtained from a certain type of rock.

This salt is called rock salt.

the mineral halite and Himalayan rock salt are some examples of rock salt.

This salt is used to treat many diseases.

Gravitation

The phenomenon of gravitation was discovered by Sir Isaac newton.

Unit of Gravitation Newton meter square Kg minus square.

Formulae=fd square

m1m2

Value of small g = 9.8 m/s square.

Mass of earth = 6 x (10 x 24 ) Kg.

Radius of earth = 6.4 x ( 10 x 5 ) m.

Kepler's Law

1. The orbit of a planet is an ellipse with the sun and sun the is one of the focus. of an ellipse.

2. The line joining of the sun and a planet sweeps equal areas in equal intervals of time.

3. The square of the time of revolution of the planet around the sun is directly proportional to the cube of the mean distance of the sun and planet.