cbse Chemisrty Amazing Facts

Hydrogen is the first element on the periodic table. It has an atomic number of 1. It is highly flammable and

is the most common element found in our universe. Morehydrogen facts.

Liquid nitrogen boils at 77 kelvin (−196 °C, −321 °F). More nitrogen facts.
Around 1% of the sun’s mass is oxygen. More oxygen facts.
Helium is lighter than the air around us so it floats, that's why it is perfect for
the balloons you get at parties. More helium facts.
Carbon comes in a number of different forms (allotropes), these include diamond, graphite and impure forms such as coal. More carbon facts, diamond facts, and coal facts.
Although it is still debated, it is largely recognized that the word 'chemistry' comes from an Egyptian word meaning 'earth'.
The use of various forms of chemistry is believed to go back as long ago as the Ancient Egyptians. By 1000 BC civilizations were using more complex forms of chemistry such as using plants for medicine, extracting metal from ores, fermenting wine and making cosmetics.
Things invisible to the human eye can often be seen under UV light, which comes in handy for both scientists and detectives.
Humans breathe out carbon dioxide (CO2). Using energy from sunlight, plantsconvert carbon dioxide into food during a process called photosynthesis.
Chemical reactions occur all the time, including through everyday activities such as cooking. Try adding an acid such as vinegar to a base such as baking soda and see what happens!
Above 4 °C, water expands when heated and contracts when cooled. But between 4 °C and 0 °C it does the opposite, contracting when heated and expanding when cooled. Stronger hydrogen and oxygen bonds are formed as the water crystallizes into ice. By the time it's frozen it takes up around 9% more space.
Often formed under intense pressure over time, a crystal is made up of molecules or atoms that are repeated in a three dimensional repeating pattern. Quartz is a well known example of a crystal.
Athletes at the Olympic Games have to be careful how much coffee they drink. The caffeine in coffee is a banned substance because it can enhance performance. One or two cups are fine but they can go over the limit with more than five. (update - as of 2004 caffeine has been taken back off the WADA banned list but its use will be closely monitored to prevent future abuse by athletes.)

Hydrogen Facts

The chemical symbol of hydrogen is H. It is an element with atomic number 1, this means that 1 proton is found in the nucleus of hydrogen.
Hydrogen is the lightest, simplest and most commonly found chemical element in the Universe, making up around 75% of its elemental mass.
Hydrogen is found in large amounts in giant gas planets and stars, it plays a key role in powering stars through fusion reactions.
Hydrogen is one of two important elements found in water (H2O). Each molecule of water is made up of two hydrogen atoms bonded to one oxygen atom.
In 1766, during an acid metal reaction, Henry Cavendish first formally recognized hydrogen. In 1781 he also found that hydrogen produces water when burned. While Cavendish is usually given credit for the discovery of hydrogen as an element, it had been produced by earlier scientists who were unaware of hydrogen as a unique chemical element.
It wasn’t until a few years later (1783) that hydrogen was given its name. The word hydrogen comes from the Greek word hydro (meaning water) and genes (meaning creator).
Hydrogen gas has the molecular formula H2. At room temperature and under standard pressure conditions, hydrogen is a gas that is tasteless, odorless and colorless.
Hydrogen can exist as a liquid under high pressure and an extremely low temperature of 20.28 kelvin (−252.87°C, −423.17 °F). Hydrogen is often stored in this way as liquid hydrogen takes up less space than hydrogen in its normal gas form. Liquid hydrogen is also used as a rocket fuel.
Under extreme compression hydrogen can also make a transition to a state known as metallic hydrogen. Laboratory research into this area is ongoing as scientists continue efforts to produce metallic hydrogen at low temperature and static compression

Nitrogen Facts
Nitrogen is a chemical element with the symbol N and atomic number of 7.
Under normal conditions nitrogen is a colorless, odorless and tasteless gas.
Nitrogen makes up around 78% of the air you breathe.
Nitrogen is present in all living things, including the human body and plants.
Nitrogen gas is used in food storage to keep packaged or bulk foods fresh. It is also used in the making of electronic parts, for industrial purposes and has many other useful applications.
Nitrogen gas is often used as an alternative to carbon dioxide for storing beer in pressurized kegs. The smaller bubbles it produces is preferred for some types of beer.
Titan, the largest moon of Saturn, has an atmosphere nearly entirely made of nitrogen (over 98%). It is the only moon in our solar system known to have a dense atmosphere.
Nitrogen is in a liquid state when at a very low temperature. Liquid nitrogen boils at 77 kelvin (−196 °C, −321 °F). It is easily transported and has many useful applications including storing items at cold temperatures, in the field of cryogenics (how materials behave at very low temperatures), as a computer coolant (a fluid used to prevent overheating), removing warts and much more.
Decompression sickness (also known as the bends) involves nitrogen bubbles forming in the bloodstream and other important areas of the body when people depressurize too quickly from scuba diving. Similar situations can occur for astronauts and those working in unpressurized aircraft.
Nitrous oxide (also known as laughing gas or by its chemical formula N2O) is used in hospitals and dental clinics as an anesthetic (removing or reducing pain and general awareness for various surgeries).
Nitrous oxide is also used in motor racing to increase the power of engine and speed of the vehicle. When used for this purpose it is often referred to as nitrous or NOS.
Nitrous oxide is a considerable greenhouse gas and air pollutant. By weight is has nearly 300 times more impact than carbon dioxide.
Nitroglycerin is a liquid used to create explosives such as dynamite. It is often used in the demolition and construction industries as well as by the military.
Nitric acid (HNO3) is a strong acid often used in the production of fertilizers.
Ammonia (NH3) is another nitrogen compound commonly used in fertilizers.




Oxygen Facts
Oxygen is an element with the chemical symbol O and atomic number 8.
Oxygen is a very reactive element that easily forms compounds such as oxides.
Under standard temperature and pressure conditions two oxygen atoms join to form dioxygen (O2), a colorless, tasteless and odorless gas.
Oxygen is essential to human life, it is found in the air we breathe and the water we drink (H20).
Oxygen makes up around 21% of the air you breathe. It is also the most common element in the Earth’s crust (around 47%) and the third most common element in the Universe (but far less than hydrogen and helium, the two most common).
The large amount of oxygen on Earth is supported by the oxygen cycle which involves the movement of oxygen between the air, living things and the Earth’s crust. Photosynthesis (a process that converts carbon dioxide into organic compounds using sunlight) plays a major role in this cycle.
Ozone (O3) is an allotrope (different form) of oxygen that combines three oxygen atoms together. While ground level ozone is an air pollutant, the ozone layer in the Earth’s upper atmosphere provides protection from the suns harmful rays by filtering UV light.
The sun’s mass is made up of around 1% oxygen.
Between 1770 and 1780, Swedish pharmacist Carl Wilhelm Scheele, British clergyman Joseph Priestley and French chemist Antoine Laurent Lavoisier researched, documented and helped discover oxygen. The name oxygen was first used by Lavoisier in 1777.
Oxygen therapy is used as a common medical treatment. You may have seen patients on TV or in real life using an oxygen mask or nasal cannula (a plastic tube that fits behind the ears and delivers oxygen through the nostrils).
Oxygen has a number of other practical uses such as smelting metal from ore, water treatment, as an oxidizer for rocket fuel and a number of other industrial, chemical and scientific applications.
Concentrated oxygen promotes fast combustion. While a spark or heat is still needed to start a fire, having concentrated oxygen near various fuels can be very dangerou