Followings are the physical characteristics of minerals:

(i)External crystal form — determined by internal arrangement of the molecules — cubes, octahedrons, hexagonal prisms, etc.

(ii)Cleavage — tendency to break in given directions producing relatively plane surfaces — result of internal arrangement of the molecules — may cleave in one or more directions and at any angle to each other.

(iii)Fracture — internal molecular arrangement so complex there are no planes of molecules; the crystal will break in an irregular manner, not along planes of cleavage.

(iv)Lustre — appearance of a material without regard to colour; each mineral has a distinctive lustre like metallic, silky, glossy etc.

(v)Colour — some minerals have characteristic colour determined by their molecular structure — malachite, azurite, chalcopyrite etc., and some minerals are coloured by impurities. For example, because of impurities quartz may be white, green, red, yellow etc.

Followings are the physical characteristics of minerals:

(i)External crystal form — determined by internal arrangement of the molecules — cubes, octahedrons, hexagonal prisms, etc.

(ii)Cleavage — tendency to break in given directions producing relatively plane surfaces — result of internal arrangement of the molecules — may cleave in one or more directions and at any angle to each other.

(iii)Fracture — internal molecular arrangement so complex there are no planes of molecules; the crystal will break in an irregular manner, not along planes of cleavage.

(iv)Lustre — appearance of a material without regard to colour; each mineral has a distinctive lustre like metallic, silky, glossy etc.

(v)Colour — some minerals have characteristic colour determined by their molecular structure — malachite, azurite, chalcopyrite etc., and some minerals are coloured by impurities. For example, because of impurities quartz may be white, green, red, yellow etc.

Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.

• Seafloor spreading helps explain continental drift in the theory of plate tectonics.

• This theory was proposed by Hess in 1961. He argued that constant eruptions at the crest of oceanic ridges cause the rupture of the oceanic crust and the new lava wedges into it, pushing the oceanic crust on either side. Thus,the ocean floor spreads.

• The younger age of the oceanic crust as well as the fact that the spreading of one ocean does not cause the shrinking of the other, made Hess think about the consumption of the oceanic crust.

• He further maintained that the ocean floor that gets pushed due to volcanic eruptions at the crest, sinks down at the oceanic trenches and gets consumed.

SEA FLOOR SPREADING
1 .it was proposed by Hess in 1961
2. he believed that new lava pushes out the plates from the mid-oceanic ridge
3. palaeomagnetic studies of the ocean floor reveal that
A. along the mid-oceanic ridge there is an intense volcanic eruption
B. huge amount of lava comes out along the mid-Atlantic ridges
C. the equidistant rock formations have similar age and chemical compositions & magnetic properties
7. rocks closer to the mid-oceanic ridges are young and normal polarity
8. The age of rocks increases as the distance increases from the mid-oceanic ridge
9. Oceanic crust is much younger(200my) than continental crust (3200my)
10. The sediments of ocean floor is very thin

Plate tectonics affects humans in several important ways.

• It causes earthquakes
• It causes volcanism
• It induces recycling of elements within the biosphere and between the geosphere and biosphere
• It causes mountain-building

Types of plate boundaries:

Plate Boundaries mainly consists of three types (fourth is a mixed type), formed in the manner the plates shift in relative to each other. These are collectively referred to as surface phenomena of different types. Plate boundaries are of different types, namely:

Transform boundaries:

These boundaries happen where two lithospheric plates move apart, or maybe further precisely, collide away from one other despite the transform faults, where plates are neither created nor destroyed.

Divergent boundaries:

These boundaries happen when both plates move apart from one other.

Convergent boundaries:

These boundaries happen where both plates move towards one other to form a zone of subduction or a continental collision.

The forces were:

(i)Pole fleeing force
(ii)Tidal force

The convectional currents in the mantle are generated due to radioactive elements causing thermal differences in the mantle portion. The currents move in radial direction and develop in cell patterns.

Drift Theory :
(i)Continental drift theory by Wegener assumes all the present continents to have arisen by the breaking and then drifting of the components of the Super - continent Pangaea.
(ii)Continental drift theory only considers the horizontal movement.
(iii)Continental drift theory mostly relies on circumstantial evidences of Jig-Saw-Fit, fossils, place deposits etc.
(iv) Continental drift theory relies on the concept of plate tectonics to be validated.
Plate Tectonics :
(i)Plate Tectonics assumes the whole earth’s lithosphere  to be divided into different ‘major’ and ‘minor’ plates which are constantly moving.
(ii)Plate tectonics takes into account the subduction of plates also.
(iii)Plate tectonics is based on scientific analysis of the processes inside the earth’s surface.

(iv)Plate tectonic theory validates the drift theory and is not to be validated by the same.

Plate tectonics is the theory that Earth’s outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like a hard and rigid shell compared to Earth’s mantle. This strong outer layer is called the lithosphere.

The earth’s lithosphere is composed of seven or eight major plates and many minor plates. The lithosphere is a rigid outermost shell of earth and is broken up into tectonic plates. When these plates meet, their relative motion determines the type of boundary like convergent, divergent, or transform.

Volcanic activity, earthquakes, mountain-building, and oceanic trench formation occur along these plate boundaries. The relative movement of the plates typically ranges from zero to 100 mm annually.

• Continental drift theory was proposed by Alfred Wegener in 1912.
• It was first put forward by Abraham Ortelius in 1596 before fully being developed by Alfred Wegener.
• The theory deals with the distribution of the oceans and the continents.
• According to Wegener’s Continental Drift theory, all the continents were one single continental mass (called a Super Continent) – Pangaea and a Mega Ocean surrounded this supercontinent. The mega ocean is known by the name Panthalassa.
• Although Wegener’s initial theory did not cover mantle convection until Arthur Holmes later proposed the theory.
• The supercontinent was named Pangaea (Pangea) and the Mega-ocean was called Panthalassa.
• According to this theory, the supercontinent, Pangaea, began to split some two hundred million years back.

Convergent boundary
1.When two plates move towards each other they are called converging.
2.Convergence of two plate boundaries leads to the folding of land and formation of mountains.
3.When they converge, subduction takes place and lithosphere is being consumed.Hence it is also called as destructive plate boundaries.

Divergent boundary
1.When two plates move away from each other they are called diverging.
2.Divergence of two plate boundaries causes the fracture in landforms.
3.When they diverge, new lithosphere is being formed by accretion.Hence it is also called as constructive plate boundaries..

Catchment of small rivulets and rills are often referred to as watersheds. Watersheds are smaller in area.

A strait is a narrow body of water that connects two larger bodies of water. It may be formed by a fracture in an isthmus, a narrow body of land that connects two bodies of water. The definition of a strait is a difficulty or a hard situation. An example of a strait is a poor family being in “dire straits.” Strait is narrow waterway between two larger bodies of water. An example of a strait is the Bering Strait. A strait is a narrow passage of water which connects two large water bodies.

India's having Long coastline is boon as well as bane also but it can be short out by some policies
India's coastline is roughly 7,500 km on West Arabian sea and Bay of Bengal in East this long coastline provides India large advantages
1) maritime trade - allows India to trade most of the world countries
2) tourism - a long coastline is very well known for tourism e.g, TN,Kerala, Goa
3) low cost of imports and exports - through sea transport it's cheaper than land
4) monsoon - swm is also known as real finance minister of India , good amount of rainfall
5) safety - from land sea coastline is considered as more safer
6) resources - India's largely dependent on the sea for fishing and India is the largest fishing industry
Some bane's are
1) disaster - Indian ocean is prone to tsunami
2) security terrorist activities, smuggling, trafficking,illegal fishing
3) piracy - from Somalian region many hijacking of ships
4) naval competition

A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since ancient times on walls of caves , but became more prevalent during the Enlightenment. Sometimes, the technique uses a three-dimensional visualization which is then projected onto a two-dimensional surface. The word graph is sometimes used as a synonym for diagram.

The term "diagram" in its commonly used sense can have a general or specific meaning:

visual information device : Like the term "illustration", "diagram" is used as a collective term standing for the whole class of technical genres, including graphs, technical drawings and tables.

Pangaea formed through a gradual process spanning a few hundred million years. Beginning about 480 million years ago, a continent called Laurentia, which includes parts of North America, merged with several other micro-continents to form Euramerica. Euramerica eventually collided with Gondwana, another supercontinent that included Africa, Australia, South America and the Indian subcontinent.

Earth crust is the thinnest and the most rudimentary layer that makes up the Earth, and yet, everything that has ever lived on Earth has called it home. The crust is a dynamic structure and it is one of the layers that make up our pale blue dot. The crust is referred to as a chemical layer that has varying chemical compositions. 

The temperature within the Earth is very high, because it has very much humidity, hot lava. This causes the rocks also becomes hot called magma. There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements.

When we go inside the earth a pressure is exerted because of the gas particles in the air—like particles of all fluids—are constantly moving and bumping into things, they exert pressure. The pressure exerted by the air in the atmosphere is greater close to Earth's surface and decreases as you go higher above the surface.

The pressure in the Earth's inner core is slightly higher than it is at the boundary between the outer and inner cores: it ranges from about 330 to 360 gigapascals.

Pressure also increases in the outer core due in part to the weight of the crust and mantle above. The Earth's magnetic field is generated by the outer core.

The density of the Earth is 5.513 g/cm³. This is an average of all of the material on the planet. Water is much less dense than iron, hence an average is needed for ease of use. Earth is the most dense planet in the Solar System; however, if gravitational compression where factored out, the second most dense planet, Mercury, would be more dense. 

The following are the immediate hazardous effects of Earthquake:

• Shaking of ground
• The disparity in ground settlement
• Natural disasters like Tsunami, landslide, mudslides, and avalanches
• Soil liquefaction
• Ground lurching and displacement
• Floods and fires
• Infrastructure collapse.

The crust is a silicate solid, the mantle is a viscous molten rock, the outer core is a viscous liquid, and the inner core is a dense solid. The difference in temperature in the mantle accounts for the density of rocks. ... The core consists of extremely hot metal layers instead of rock. Iron and nickel make up the outer section of the core, while the interior is almost entirely iron. The inner core is almost totally solid and shaped like a ball.

Knowledge of the earth's interior is based on indirect observation as it is impossible to collect data regarding the earth's interior, we can't dig on such a great extent ,as their is intolerable heat deep inside the earth and it is impossible for any organism to survive their.. Therefore the the observation including the earth's interior is based on indirect observations like soil exposed on the surface after earthquake or rocks formed after cooling of magma.

Seismic waves from large earthquakes pass throughout the Earth. These waves contain vital information about the internal structure of the Earth. As seismic waves pass through the Earth, they are refracted, or bent, like rays of light bend when they pass through a glass prism. All the three, P, S and L waves follow curved paths in the interior of the earth which proves that density increases inside the earth. P and S waves are recorded along the surface upto a distance of 11000 km from the focus of the earthquake. Their velocity also increases with the increase in the depth upto 2900 km.

Indus, Ganga, Brahmaputra, Satluj, Alaknanda, Gandak, Kosi etc are Himalayan rivers

• The atmosphere protects the Earth from the solar radiation. It filters the harmful ultraviolet rays of the Sun.
• The atmosphere traps the required heat of the Sun and allows the rest to escape into space, thus maintaining a moderate temperature on the Earth. This ensures the existence of various life forms.
• Due to the friction created in the atmosphere, many meteors and meteorites get burned in the atmosphere, which would have otherwise fallen on to the surface of the Earth.
• Because of the difference in the temperature of the atmosphere, air gets circulated causing winds and the rains. All forms of life depend on these phenomena. 
• Soil absorbs nitrogen and oxygen which is present in the atmosphere. This helps plants to grow.
• The water cycle takes place due to the processes of evaporation, condensation and precipitation. Water vapour, which is a part of the atmosphere, condenses to form clouds resulting in rainfall.

• The shadow zone is the zone of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves.
• The shadow zone results from P waves being refracted by the liquid core and S waves being stopped completely by the liquid core.
• A zone between 105° and 145° from the epicenter was recognized as the shadow zone for both the wave types.
• The entire zone beyond 105° does not receive S-waves.
• The shadow zone of S-wave is larger than that of the P-waves.
• The shadow zone of P-waves appears as a band around the earth between 105° and 145° away from the epicenter.

• A gulf is a large body of water almost encircled by land except for a small mouth that opens out to the sea. A strait is a strip of water that separates two lands or two large bodies of water. • Straits are used for navigational purposes and have played an integral part when it comes to shipping routes. Gulfs are more useful for human settlements, as such areas provide easy access to the ocean while being well protected as well. • Gulfs can be easily associated with inland bodies of water as well as the ocean. Straits are mostly discussed with regards to the ocean.