Showing posts with label Sciences. Show all posts
Showing posts with label Sciences. Show all posts

General Knowledge for Competitive Examinations

General Knowledge (GK) makes Integral Part of many competitive examinations in India. The GK Test examine your awareness and abilities from in and around your surroundings. In this portion questions are asked from day to day life experiences. Generally, whether its and admission test or recruitment exam questions are asked from the areas those we discuss often among friends, family, or listen over radio, television and social media etc.

General Knowledge: CHEMISTRY

Knowledge in Chemistry is essential for day to day living. Of course its essential to make scientific discoveries, and make things work. In competitive examinations Questions in General Knowledge are asked from Chemistry. Here are lessons useful for tests like UPSC Exam, SSC Exam, Bank PO Exam, Defence Exam, Teachers' Training Exam, Admission Test, Scholarship Tests etc.

Introduction to Chemistry

Atomic Structure

Periodic Classification of Elements

Chemical Bonding

Oxidation and Reduction

General Knowledge - Environmental Science

Environment Science in academics has emerged as a new discipline. Human race did massive damage to environment and now we need to take corrective measures to keep it healthy and habitable.  Everyone should know and learn about Environment. To measure your environmental awareness, in competitive examinations questions are asked. Here are lessons about Environmental Science useful for competitive examinations like UPSC Exam, Bank PO Exam, SSC Exam, Police Service Exam, Railway Recruitment Exam, Scholarship Test, and Admission Test Etc.

Environmental Science: An Overview 

Some Environmental Facts

Energy

Waste

Ozone Layer Depletion

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

Energy

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



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

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.

Water Pollution


The pollution of water is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater), very often by human activities.
 

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.

Ecology



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.

Environmental Science: An Overview



Environment - The environment means the conditions and circumstances that surround someone. The air water and space surrounds both living and non living organisms. This surrounding is called natural environment.

Electronics



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.

Chronological Developments in Nuclear Physics

1890s
1895
November 8 - Wilhelm Roentgen discovers X-Rays
1897
Becquerel and Marie Curie discover radioactivity
1895 - 1899
Ernest Rutherford discovers alpha and beta radiation
1898
Marie and Pierre Curie isolated the two new chemical elements polonium and radium

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.