CBSE Class IX Chemistry Natural resources

NATURAL RESOURCES

Pranav Ghildiyal

IX D

Introduction To Natural Resources

The resources we get from nature are called as natural resources. These are equally important for the survival of human beings. There are two main natural resources :-

(i) Water(ii) Air(iii) Others are :- Plants Coal, fossil fuels, rock and mineral resources Forestry Soils Water, oceans, lakes, groundwater and rivers Some resources under water and air are :- Water – water cycle, rain etc. Air – different gases and their cycles(oxygen, nitrogen)

AirAir is nothing but it is just the part of Earth's atmosphere that We humans breathe (oxygen).

Water

Water is a chemical substance with the chemical formula H2O. Its molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state, water vapor or steam.

Plants

Plants are living organisms belonging to the kingdom Plantae. The scientific study of plants, known as botany, has identified about 350,000 extant Species of plants, defined as seed plants, bryophytes, ferns and fern allies. As of 2004, some 287,655 species had been identified, of which 258,650 are flowering and 18,000 bryophytes. Green plants obtain most of their energy from sunlight by a process called photosynthesis.

Fossil fuels

Fossil fuels are fuels formed by natural resources such as an aerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years. The fossil fuels include coal, petroleum, and natural gas which contain high percentages of carbon.

Rock

In geology, rock or stone is a naturally occurring solid aggregate of Minerals and/or mineraloids. The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic. The scientific study of rocks is called petrology, and petrology is an essential component of geology.

Mineral resources

A solid inorganic substance of natural occurrence and obtained by mining. Mineral resources are those economic mineral concentrations that have undergone enough scrutiny to quantify their contained metal to a certain degree. None of these resources are ore because the economics of the mineral deposit may not have been fully evaluated.

Forestry

Forestry is the art and science of managing forests, tree plantations, and related natural resources. The main goal of forestry is to create and implement systems that allow forests to continue a  sustainable  continuation of environmental supplies and services. The challenge of forestry is to create Systems that are socially accepted while sustaining the resource and any

other resources that might be affected.

Soil

Soil is a natural body consisting of layers (soil horizons) of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical  characteristics. It is composed of particles of broken rock that have been altered by chemical and environmental processes that include weathering and erosion. Soil differs from its parent rock due to interactions between the lithosphere, hydrosphere, atmosphere, and the biosphere. It is a mixture of mineral and organic constituents that are in solid, gaseous and aqueous states

.

Ocean

An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is Customarily divided into several principal ocean and smaller seas.

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin that is surrounded by land. Lakes are inland and not part of the ocean, and are larger and deeper than ponds. Lakes can be contrastedwith rivers or streams, which are usually flowing. However most lakes are fed and drained by rivers and streams.

.

Groundwater Ground water is the water found below the surface of earth or below the soil. It is widely used by farmers for irrigating their fields. But erratic rainfall and overuse of ground water is resulting in decreasing of ground water level.

Rivers

A river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including stream, creek, brook, rivulet, tributary and rill; there is no general rule that defines what can be called a river, although in some countries or communities a stream may be defined by its size.

Air Pollution Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm Or discomfort to humans or other living organisms, or damages the natural environment into the atmosphere.

The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.

Indoor air pollution and urban air quality are listed as two of the world's worst pollution problems in the 2008 Blacksmith Institute World's Worst Polluted Places report.

WINDSWind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the out-gassing of light chemical elements from a planet's atmosphere into space. Winds are commonly classified by their spatial scale, their speed, the types of forces that cause them, the regions in which they occur, and their effect. The strongest observed winds on a planet in our solar system occur on Neptune and Saturn.

In meteorology, winds are often referred to according to their strength, and the direction the wind is blowing from. Short bursts of high speed wind are termed gusts. Strong winds of intermediate duration (around one minute) are termed squalls. Long-duration winds have various names associated with their average strength, such as breeze, gale, storm, hurricane, and typhoon. Wind occurs on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hours, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two main causes of large scale atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet (Coriolis effect). Within the tropics, thermal low circulations over terrain and high plateaus can Drive monsoon circulations. In coastal areas the sea breeze/land breeze cycle can define local winds; in areas that have variable terrain, mountain and valley breezes can dominate local winds.

Role of atmosphere in climate control and Ozone layer

The atmosphere keeps the average temperature of the Earth fairly steady during the day and even during the course of the whole year. The atmosphere prevents the sudden increase in temperature during the daylight hours. And during the night, it slows down the escape of heat into outer space.

Ozone The ozone layer is a layer in Earth's atmosphere which Contains relatively high concentrations of ozone (O3).

This layer absorbs 97–99% of the sun's high frequency ultraviolet light, which is potentially damaging to life on earth. It is mainly located in the lower portion of the stratosphere from approximately 13 km to 40 km above Earth, though the thickness varies seasonally and geographically. The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson.

BIOGEOCHEMICAL CYCLES In ecology and Earth science, a biogeochemical cycles cycle or nutrient cycle is a pathway by which a chemical element or molecule moves through both biotic (biosphere)

and abiotic lithosphere, atmosphere, and hydrosphere) compartments of Earth. In effect, the element is recycled, although in some cycles there may be places (called

reservoirs) where the element is accumulated or held for a long period of time (such as an ocean or lake for water). Water, for example,

is Always

recycled through. the

water cycle

NITROGEN CYCLE Nitrogen is required for the manufacturing of all amino acids and nucleic acids; however, the average organism can not use atmospheric nitrogen for these tasks and as a result is dependent on the nitrogen cycle as a source for its usable nitrogen. The nitrogen cycle begins with nitrogen stored in the atmosphere as N2 or nitrogen stored in the soil as ammonium (NH4+), ammonia (NH3), nitrite (NO2−), or nitrate (NO3−). Nitrogen is assimilated into living organisms through three stages: nitrogen fixation, nitrification, and plant metabolism. Nitrogen fixation is a process which occurs in prokaryotes in which N2 is converted to (NH4+). Atmospheric nitrogen can also undergo nitrogen fixation by lighting and UV radiation and become NO3-. Following nitrogen fixation, nitrification occurs. During nitrification, ammonia is converted into nitrite, and nitrite is converted into nitrate. Nitrification occurs in various bacteria. In the final stage, plants absorb ammonia and nitrate and incorporate it into their metabolic pathways. Once the nitrogen has entered the plant metabolic pathway, it may be transferred to animals when the plant is eaten. Nitrogen is released back into the cycle when denitrifying bacteria convert NO3- into N2 in the process of denitrification, when detrivorous bacteria convert organic compounds back into ammonia in the process of ammonification, or when animals excrete ammonia, urea, or uric acid.

OXYGEN CYCLE The Oxygen cycle is the biogeochemical cycle that describes the movement of

oxygen within its three main reservoirs: the atmosphere (air), the total content of biological matter within the biosphere (the global sum of all ecosystems), and the lithosphere (Earth's crust). Failures in the oxygen cycle within the hydrosphere (the combined mass of water found on, under, and over the surface of a planet) can result in the development of hypoxic zones. The main driving factor of the oxygen cycle is photosynthesis, which is responsible for the modern Earth's atmosphere and life.

CARBON CYCLE Carbon is continuously cycled between the oceans, land, and the atmosphere. The atmospheric carbon is primarily carbon dioxide. Carbon,

on land, occurs primarily in living biota and decaying organic matter. Dissolved carbon dioxide and small organisms like plankton that store carbon dioxide are major sources in the ocean. Carbon is measured in Gigatons, with the deep ocean containing almost 40,000 Gt, compared to about 2,000 Gt on land and 750 Gt in the atmosphere.

Carbon dioxide, a known "greenhouse gas", traps some of the radiation in the atmosphere that would be lost in space. This causes the atmosphere to be warmer than it would naturally be. Since pre – industrial times man-made emissions have increased the amount of carbon dioxide in the atmosphere by about 30%. The increase in carbon dioxide causing global warming is important for us to understand so we can predict future implications concerning our planet.

GREEN HOUSE EFFECT The greenhouse effect is a process by which radiative energy leaving a planetary surface is absorbed by some atmospheric gases, called greenhouse gases. They transfer this energy to other components of the atmosphere, and it is re-radiated in all directions, including back down towards the surface. This transfers energy to the surface and lower atmosphere, so the temperature there is higher than it would be if direct heating by solar radiation were the only warming mechanism. This mechanism is fundamentally different from that of an actual greenhouse, which works by isolating warm air inside the structure so that heat

is not lost by convection. The greenhouse effect was discovered

by Joseph Fourier in 1824, first reliably

experimented on by John Tyndall in 1858, and first reported quantitatively by

Svante Arrhenius in 1896.

Mineral Riches In The Soil There are three main mineral riches of the soil. These are :- The sun :- The sun heats up rocks during the day so that they expand. At night these rocks cool down and contract. Since all parts all parts of the rock do not expand and contract at the same rate, this results in the formation of cracks and ultimately the huge rocks Break up into smaller pieces.

Water :- Water helps in the formation of soil in two ways. First, water could get into the cracks in the rocks formed due to uneven heating by the Sun. if this water later freezes, it would cause the cracks to widen. Second, Flowing water wears away even hard rock over long periods of time. Fast Flowing water often carries big and small particles of rock downstream. The water then takes these particles along with it and deposits it further down its path. Soil is thus found in

places far away from its parent- rock.

Wind :- strong winds erode the rocks. Wind carries sand

from one place to other

RAIN Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface. On Earth, it is the condensation of atmospheric

water vapour into drops of water heavy enough to fall, often making it to the surface. Two processes, possibly acting together, can lead to air becoming saturated leading to rainfall: cooling the air or adding water vapor to the air. Virga is precipitation that begins falling to the earth but evaporates before reaching the surface; it is one of the ways air can become saturated. Precipitation forms via collision with other rain drops or ice crystals within a cloud. Rain drops range in size from oblate, pancake-like shapes for larger drops, to small spheres for

smaller drops.

WATER CYCLE The water cycle, also known as the hydrologic cycle or H2O cycle,

describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapour, and ice at various places in the water cycle. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, runoff, and subsurface flow. In so doing, the water goes through different phases: liquid, solid, and gas.

The hydrologic cycle also involves the exchange of heat energy, which leads to temperature changes. For instance, in the process of evaporation, water takes up energy from the surroundings and cools the environment. Conversely, in the process of condensation, water

releases energy to its surroundings, warming

the environment..

WATER POLLUTION Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrheal sickness every day. Some 90% of China's cities suffer from some degree of water pollution and nearly 500 million people lack access to safe drinking water. In addition to the acute problems of water pollution in developing countries, industrialized countries continue to struggle with pollution problems as well.In the most recent national report on water quality in the United States, 45 percent of assessed stream miles, 47 percent of assessed lake acres, and 32 percent

of assessed bay and estuarine square miles were classified as polluted.

Water is typically referred to as polluted when it is impaired by anthropogenic  contaminants and either does not support a human use, like serving as drinking water, and/or undergoes a marked shift in its ability to support its constituent biotic communities, such as fish. Natural phenomena such as volcanoes, algae, blooms, storms, and earthquakes also cause major changes in water quality and the ecological status of water.

CONCLUSION Natural resources are resources which we get from nature and which are formed without any human interference. Like coal, petroleum etc. these were formed years ago by natural

processes. These resources are very important for survival

of human beings

NATURAL RESOURCES ARE VERY IMPORTANT

SAVE THEM