Skip to main content


Showing posts from December 5, 2017

Glossary – Environmental Science

Abundance – This refers to the number or amount of something found in the environment, generally in plenty.

Acid precipitation- This refers to the acidic rain, snow, or dry particles set down from the air owing to increased acids released by anthropogenic or natural resources.

Acids- This refers to the substances that liberate hydrogen ions (protons) in water.

Some Environmental Facts

The biggest energy source on the surface of the earth is Solar radiation The acid found in soil is Humic acid Burning of fossil fuels releases Carbon-di-oxide The place referred to as the Valley of Death is Cubatao in Brazil


The energy is the ability to do work. In India 70% population resides in rural areas; thus supplying energy to villages is vital to maintain pace in development. 21% of villages and nearly 50% rural households are yet not electrified.

The per capita consumption of energy was 4816 KWH in 2010-11, according to Central Statistics Office.


Disaster is a sudden, calamitous event bringing great damage, loss, and destruction and devastation to life and property. The damage caused by disasters is immeasurable and varies with the geographical location, climate and the type of the earth surface/degree of vulnerability. This influences the mental, socio-economic, political and cultural state of the affected area.


Waste, or rubbish, trash, junk, garbage, depending on the type of material or the regional terminology, is an unwanted or undesired material or substance. It may consist of the unwanted materials left over from a manufacturing process (industrial, commercial, mining or agricultural operations,) or from community and household activities. The material may be discarded or accumulated, stored, or treated (physically, chemically, or biologically), prior to being discarded or recycled. It is also used to describe something we use inefficiently or inappropriately.

Ozone Layer Depletion

Ozone is composed of three oxygen molecules and. is produced naturally by sunlight. At ground level ozone is a pollutant, but in the upper stratosphere (a segment of atmosphere extending approximately 9 miles to 30 miles above the earth's surface) it forms a layer that protects the earth from the sun's harmful ultraviolet radiation. Although ozone composes a small part of the atmosphere's total mass, it absorbs more than 99% of the sun's ultraviolet radiation.

Acid Rain

Acid rain is rain consisting of water droplets that are unusually acidic because of atmospheric pollution - most notably the excessive amounts of sulfur and nitrogen released by cars and industrial processes. Acid rain is also called acid deposition because this term includes other forms of acidic precipitation such as snow.

Marine Pollution

Marine pollution refers to ocean contamination, especially with man-made waste or byproducts. This is considered to be a severe problem by many environmentalists, since it can have detrimental and lasting effects on the global marine ecosystem. There are several types of marine pollution, each of which has the potential to harm the delicate balance of life.

Land pollution

Land pollution is the deterioration (destruction) of the earth’s land surfaces, often directly or indirectly as a result of man’s activities and their misuse of land resources.
It occurs when waste is not disposed off properly, or can occur when humans throw chemicals unto the soil in the form of pesticides, insecticides and fertilizers during agricultural practices. Exploitation of minerals (mining activities) has also contributed to the destruction of the earth’s surface.

Global Warming

Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect.


What is Ecology?
Ecology is the study of the distribution and abundance of organisms, the interaction between organisms, the interaction between organisms and their environment, and structure and function of ecosystems.


Electronics – Electronics is the branch of physics and technology that deals with the emission, behavior, and effects of electrons and with electronic devices.
Most electronic devices use semiconductor components to perform electron control. The study of semiconductor devices and related technology is considered a branch of solid state physics, whereas the design and construction of electronic circuits to solve practical problems come under electronics engineering. This article focuses on engineering aspects of electronics.

Timeline: Nuclear Treaties & Agreements

1963 Limited Test Ban TreatyAn agreement between the US, USSR, and UK which prevented nuclear testing above ground, underwater, and in outer space. But it does allow testing to occur underground as long as the radioactive fallout is not widespread. A total of 116 countries have signed this, and China, who had not signed, did testing in 1992 that violated the treaty's guidelines.

Atomic and Nuclear Physics

Atoms - Atoms are the smallest unit of an element that chemically behaves the same way the element does. When two chemicals react with each other, the reaction takes place between individual atoms at the atomic level.
Atomic Structure
In the early 20th century, a New Zealand scientist working in England, Ernest Rutherford, and a Danish scientist, Niels Bohr, developed a way of thinking about the structure of an atom that described an atom as looking very much like our solar system. An atom is composed of three basic particles – electrons, protons and neutrons.Nucleus of an atom consists of protons and neutrons.Electrons revolve in atomic orbit.


Magnetism - Magnetism is a force of attraction or replusion that acts at a distance. It is due to a magnetic field, which is caused by moving electrically charged particles or is inherent in magnetic objects such as a magnet.
Magnetism - A magnet is an object that exhibits a strong magnetic field and will attract materials like iron to it. Magnets have two poles, called the north (N) and south (S) poles. Two magnets will be attacted by their opposite poles, and each will repel the like pole of the other magnet. Magnetism has many uses in modern life.

Current Electricity

Electric Current - The Electric current is a flow of electric charge through a conductive medium.

In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in a plasma.

The SI unit for measuring the rate of flow of electric charge is the ampere, which is charge flowing through some surface at the rate of one coulomb per second. Electric current is measured using an ammeter.

Static Electricity

Static electricity is an excess of electric charge trapped on the surface of an object. The charge remains until it is allowed to escape to an object with a weaker or opposite electrical charge, such as the ground, by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, which flows through wires or other conductors and transmits energy.


Light is a type of energy which propagates as electromagnetic waves. In the spectrum of electromagnetic waves, light has place between ultraviolet and infrared region.

Some Facts About Light

•    Electromagnetic waves are transverse waves, therefore, light is also transverse wave.
•    Wave nature of light explains; rectilinear propagation of light, reflection of light, refraction of light, interference of light, diffraction of light and polarization of light.
•    The happenings in physics like Photoelectric Effect and Compton Effect can not be explained on the basis of wave nature of light. These phenomenons are explained on the basis of quantum theory of light, explained by Albert Einstein.
•    The quantum theory of light, considers light as a packet or bundle of energy, these energy packets are called photons. Photon associates with it as Energy E; where E = hv
•    Light has dual nature and behaves as a particle as well as wave.
•    Speed of Light was first calculated by Roemer in 16…


First Law of Thermodynamics
The first law of thermodynamics is the application of the conservation of energy principle to heat and thermodynamic processes:

The change in internal energy of a system is equal to the heat added to the system minus the work done by the system.

Mathematically, ΔU (Change in Internal Energy) = Q (Heat added to or drawn from the system) – W (Work done by the system)


Heat may be defined as energy in transit from a high temperature object to a lower temperature object.
Some Characteristics of Heat and Mathematical Equivalent
•    Heat is also defined as the transfer of kinetic energy from one medium or object to another, or from an energy source to a medium or object.

•    The heat transfer can occur in three ways: radiation, conduction, and convection.

•    The standard unit of heat in the International System of Units (SI) is the calorie (cal).

•    One calorie is defined as the amount of energy transfer required to raise the temperature of one gram of pure liquid water by one degree Celsius, provided the water temperature is higher than the freezing point and lower than the boiling point.

•    Sometimes the kilocalorie (kcal) is specified as a unit of heat; 1 kcal = 1000 cal. This is the also called diet calorie.

•    The amount of heat contained in a body depends upon the mass of the body.

•    If W is work performed and Heat produced is H, then W/H …

Sound Waves

•    Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving.
•    If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it.
•    The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.
•    The mechanical vibrations which can be said as sound are able to travel through all forms of matter i.e. solids, liquids and gases. The matter which allows the sound to travel through it is called the medium.
•    Sound cannot travel through a vacuum.