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Wednesday, July 17, 2013

Preparation of Chloroform (CHCL3)

REQUIRED MATERIALS:
 - A glass tumbler or container
 - A syringe or similar
 - 10ml of acetone
 - at least 500ml of household bleach (NaCLO)

PROCESS:
  1. Start pouring bleach solution of required above mentioned volume on a glass container.
  2. Then after pour 10ml of acetone of glass container using syringe or similar.
  3. Place the mix in a dark cool place (not inside)
 Now, let react for a couple of hours. Then, after chloroform is prepared.

WARNING:
  If you are using industrial bleach then use only 200ml because  it is three times more concentrated than household bleach. Chloroform usually contains an amount of very toxic phosygene, formed upon contact with (O2) oxygen and light. Chloroform has strong narcotic properties so, avoid breathing on fumes. Stay safe take care and enjoy every experiments of science.
Taking this experiment as a play may really cause a great loss or damage of life and property because sodium metal is really very explosive when it contacts with moist and water directly and can cause a fire. So, it is better to carry out this experiment outside the houses or schools. Recommended place for carrying out this experiment is at safe experimental laboratories or at open and vacant places . Always be careful while making Na Metal. Being safe and doing safe is best method to learn each and every experiments of Chemistry Science.
With best wishes!
                                                                                            Administrative of blog: Bikash Pokharel

DNA (Deoxyribo Nucleic Acid)



Double helical structure of DNA molecule:


                  DNA is mainly found in the nucleus. A small amount of DNA is also found in mitochondria and   chloroplast. It a macromolecule formed by the end to end polymerization of a large number of repeated units called deoxyribonucleotides or simply nucleotides.
Each nucleotide is formed by cross-linking of three substances:
                                     i.            Deoxyribose Sugar: The DNA molecules contain deoxyribose sugar and hence, it is       called deoxyribo nucleic acid. Deoxyribose is a pentose sugar (with 5-carbon atoms).
                                     ii.            Phosphate: The phosphate in the DNA is present as phosphoric acid (H3PO4). Each   phosphate group is joined to a carbon atom 3’ of one deoxyribose sugar and to carbon atom 5’ of another deoxyribose sugar.
                                     iii.            Nitrogenous Bases: The nitrogenous bases are of two types: Purine and Pyrimidine.
a)      Purine: It is a double ringed structure. It contains Adenine (A) and Guanine (G).
b)      Pyrimidine: It is a single ringed structure. It contains Cytosine (C) and Thymine (T).
Nucleotides and nucleosides:
A sugar molecule with nitrogenous base forms a nucleotide. The nucleosides in DNA are called deoxyribonucleosides and nucleotides are called deoxyribonucleotides.
Nitrogenous base + sugar= Nucleoside
Nucleoside + phosphate= Nucleotide
Or
Nitrogenous base + sugar +phosphate= Nucleotide
DNA is a double helix or double stranded structures. By definition of a helix:
Double helix: The structure of DNA with the two strands of DNA spiraling about one other.
The double helix looks something like an immensely long ladder twisted into a helix, or coil. The sides of the "ladder" are formed by a backbone of sugar and phosphate molecules, and the "rungs" consist of nucleotide bases joined weakly in the middle by hydrogen bonds.




How 'obesity gene' makes people fat

Scientists have reveled how a gene long associated with obesity makes people fat by triggering increased hunger, opening up potential new ways to fight a growing global health problem. A common variation in the FTO gene affects one in six of the population, making them 70 percent more likely to become obese- but until now experts did not know why.
       Using a series of tests, a British -led research team said they had found that people with the variation not only had higher levels of the 'hunger hormone' ghrelin in their blood but also increased sensitivity to the chemicals in their brains. "It's a double hit." said Rachel Batterham from University College, London, who led the study, which was published in the Journal of Clinical Investigation today. The discovery follows the studies of blood samples from the people after meals, combined with functional magnetic resonance imaging  of volunteers' brains and cell-based studies looking at ghrelin production at a molecular level.
     







 Batterham said the work provided new insights and possible new leads for treatment, since some experimental drugs are known to suppress ghrelin and could be particularly effective if targeted at patients with the obesity-risk variant of the gene. Previous research has also shown that ghrelin can be reduced by eating a high- protein diet.At least 2.8 millions adults die each year as a result of being overweight or obese and more than 40 million children under the age of five were overweight in 2011, according to the World Health Organization (WHO).
So, developing effective obesity drugs has been a challenge for drugmakers, although some new medicines are now coming through.
       

Electromagnetic waves along with thier properties

A wave motion refers to a carrier medium of energy from one particular point to another without there being any kind of transfer of any matters between these two points. Waves may be classified as being either mechanical or electromagnetic. A mechanical wave is the disturbance that requires a material medium for it's propagation, e.g., water waves, waves in stretched strings, etc. It is also known as elastic waves. The electromagnetic waves are the waves in which the various of electric and magnetic filed take place during their propagation, e.g., visible light rays, x-rays, gamma-rays, radio waves, etc. They can travel through a vacuum. The solar radiation which we receive everyday is also electromagnetic waves.
       Infrared radiation, visible light and ultraviolet radiation are all members of the same electromagnetic spectrum. Some common properties of electromagnetic waves are as follows:
1. All electromagnetic waves travel through a medium or in a vacuum at the same speed i.e., 3*10^8 ms-1.
2. They are unaffected by electric and magnetic fields.
3. They are transverse wave.
4. The wave equation "speed= frequency*wavelength" can be applied.
5. They all, under suitable conditions, can be reflected, refracted and diffracted.
                                            They are characterized by their different frequencies (or wavelengths). Ultraviolet radiation has a greater  frequency than visible light and infrared has a lower frequency than visible light.

Saturday, June 1, 2013

What science suggests about the ways to handle exam pressure?

Simply, science defines pressure as a force acting per unit of area,  i.e P=F/A. but in case of exam pressure science defines pressure as a force acting on per unit bits of mind and memory of a student. Students study throughout the year, but preparing for exams is a different deal altogether . So, what science suggests ways to handle exam pressure? of course science has elaborated few points and tricks to handle the trauma. they are following:












1. Eat and Sleep well: students have 10,000 pages to read but that does not mean them to stop doing everything and just turn themselves into a mugging-up machine. but science approves that students need to eat and sleep well; not the fatty and spicy foods but foods,drinks and fruits that are rich in vitamins, minerals and proteins are to be taken and well sleep is must to provide enough rest to your body.
2. Make reading and writing one of your interest: Science approves that every human mind is equally brilliant only the difference is the way one use it. so, to achieve all the knowledge perfectly first take reading and writing interestingly. give equal interest to study as you give to your sports and movies. this will 100% help you to face exam easily.
3. Remove all the nervousness from your mind: Many of the students have the habit of nervousness during exam due to which they even forget the things they know. so, science suggests all students appearing exam must be calm and consistent making their mind just focus on exam questions and the things they have prepared for exam.
4.Discuss and practice (1000 times if possible) again and again:  There is a famous Chinese quote, i.e  I hear-I forget. I see- I remember. I do-I understand and I practice-I excel. so, more practice more understanding and more achievements of knowledge. Science says that if a person discuss and practice something for more than 1000 times then he/she will never forget the things that he/she practiced.
So, applying these four key points liberated by science, students can easily face the exam and can remove exam pressure from their mind.

Friday, May 31, 2013

Are Ghosts Real? But science doesn't claims it Real.

If you believe in ghosts, you're not alone: A 2005 Gallup poll found that 37 percent of Americans believe in haunted houses, and about one-third believe in ghosts. Tens of thousands of people around the world actively search for ghosts as a hobby. Researcher Sharon Hill of the Doubtful Newsblog counted about 2,000 active amateur ghost-hunting groups in America.
ghost in woods
Ghosts have been a popular subject for millennia, appearing in countless stories, from "Macbeth" to the Bible, and even spawning their own folklore genre: ghost stories. Ghosts are perhaps the most common paranormal belief in the world. Part of the reason is that belief in ghosts is part of a larger web of related paranormal beliefs, including near-death experience, life after death, and spirit communication.
The idea that the dead remain with us in spirit is an ancient one, and one that offers many people comfort; who doesn't want to believe that our beloved but deceased family members aren't looking out for us, or with us in our times of need? Most people believe in ghosts because of personal experience; they have seen or sensed some unexplained presence.
The science and logic of ghosts
Personal experience is one thing, but scientific evidence is another matter. Part of the difficulty in investigating ghosts is that there is not one universally agreed-upon definition of what a ghost is. Some believe that they are spirits of the dead who for whatever reason get "lost" on their way to The Other Side; others claim that ghosts are instead telepathic entities projected into the world from our minds.
Still others create their own special categories for different types of ghosts, such as poltergeists, residual hauntings, intelligent spirits and shadow people. Of course, it's all made up, like speculating on the different races of fairies or dragons: there are as many types of ghosts as you want there to be.
There are many contradictions inherent in ideas about ghosts. For example, are ghosts material or not? Either they can move through solid objects without disturbing them, or they can slam doors shut and throw objects across the room. Logically and physically, it's one or the other. If ghosts are human souls, why do they appear clothed and with (presumably soulless) inanimate objects like hats, canes, and dresses — not to mention the many reports of ghost trains, cars and carriages?
If ghosts are the spirits of those whose deaths were unavenged, why are there unsolved murders, since ghosts are said to communicate with psychic mediums, and should be able to identify their killers for the police. And so on; just about any claim about ghosts raises logical reasons to doubt it.
Ghost hunters use many creative (and dubious) methods to detect the spirits' presences, often including psychics. Virtually all ghost hunters claim to be scientific, and most give that appearance because they use high-tech scientific equipment such as Geiger counters, Electromagnetic Field (EMF) detectors, ion detectors, infrared cameras and sensitive microphones. Yet none of this equipment has ever been shown to actually detect ghosts.
Other people take exactly the opposite approach, claiming that the reason that ghosts haven't been proven to exist is that we simply don't have the right technology to find or detect the spirit world. But this, too, can't be correct: Either ghosts exist and appear in our ordinary physical world (and can therefore be detected and recorded in photographs, film, video, and audio recordings), or they don't. If ghosts exist and can be scientifically detected or recorded, then we should find hard evidence of that — yet we don't. If ghosts exist and cannot be scientifically detected or recorded, then all the photos, videos, and other recordings claimed to be evidence of ghosts cannot be ghosts. With so many basic contradictory theories — and so little science brought to bear on the topic — it's not surprising that despite the efforts of thousands of ghost hunters on television and elsewhere for decades, not a single piece of hard evidence of ghosts has been found.
Why many believe
Many people believe that support for the existence of ghosts can be found in no less a hard science than modern physics. It is widely claimed that Albert Einstein suggested a scientific basis for the reality of ghosts; if energy cannot be created or destroyed but only change form, what happens to our body's energy when we die? Could that somehow be manifested as a ghost?
It seems like a reasonable assumption — unless you understand basic physics. The answer is very simple, and not at all mysterious. After a person dies, the energy in his or her body goes where all organisms' energy goes after death: into the environment. The energy is released in the form of heat, and transferred into the animals that eat us (i.e., wild animals if we are left unburied, or worms and bacteria if we are interred), and the plants that absorb us. There is no bodily "energy" that survives death to be detected with popular ghost-hunting devices.
While most ghost hunters engage in harmless (and fruitless) fun, there can be a darker side. In the wake of popular ghost-hunting TV shows, police across the country have seen a surge in people being arrested, injured, and even killed while looking for ghosts. In 2010, a man died while ghost-hunting with a group of friends hoping to see the ghost of a train that crashed years earlier. The ghost train did not appear — but a real train came around a bend and killed one man.
The evidence for ghosts is no better today than it was a year ago, a decade ago, or a century ago. There are two possible reasons for the failure of ghost hunters to find good evidence. The first is that ghosts don't exist, and that reports of ghosts can be explained by psychology, misperceptions, mistakes and hoaxes. The second option is that ghosts do exist, but that ghost hunters are simply incompetent. Ultimately, ghost hunting is not about the evidence (if it was, the search would have been abandoned long ago). Instead, it's about having fun with friends, telling stories, and the enjoyment of pretending they are searching the edge of the unknown. After all, everyone loves a good ghost story.

  References from: Benjamin Radford is deputy editor of "Skeptical Inquirer" science magazine and author of six books, including "Scientific Paranormal Investigation: How to Solve Unexplained Mysteries."

Make Sodium Metal (Na Metal) on your own

Sodium (chemical symbol Na) is an interesting element. It reacts in contact with both oxygen and water, and several sodium salts are used to produce a yellow color in fireworks.
The metallic form has limited uses in chemistry, and is too soft and reactive to be used as a building material. Sodium's primary use (besides forming other chemical compounds) is as a high density coolant when in liquid form. When alloyed together with potassium metal, the resulting substance is liquid at room temperature, and also used as a coolant (occasionally in nuclear reactors).
With the use of a finely powdered reactive metal such as magnesium or aluminum, sodium may be produced through a reaction with sodium hydroxide—a common drain cleaner known as lye.
This experiment uses several dangerous chemicals and there is obviously a fire hazard. Full laboratory safety gear is required, including safety glasses, chemically resistant gloves, and a lab coat. It should also not be done in a dry area or where fire could likely spread.
The reaction is as follows: 2Mg + 2NaOH -> 2MgO + 2Na + H2
This reaction works because the magnesium (Mg) is able to rip the oxygen molecule right out of the sodium hydroxide (NaOH). Sodium cannot bind to hydrogen alone, so with the oxygen gone, both remaining elements are free. The hydrogen escapes the reaction chamber and burns in contact with the air, and the sodium and magnesium oxide (MgO) is left at the bottom of the container.
Sodium will quickly begin to react with the moisture in air, once again forming sodium hydroxide and hydrogen gas. To prevent it from coming into contact with water and oxygen it must be stored under mineral oil. Many videos have circulated online and through high school science classes of large pieces being thrown into water resulting in large explosions from the rapid production and ignition of hydrogen gas. This may be a very interesting thing that can be done with sodium, but it should also be noted that the lye produced will stay in the water, and is deadly to aquatic life. It should only ever be reacted with water in isolated containers where it can do no harm.
Have fun, and stay safe!
 

EXPERIMENT TO DEMONSTRATET THE ROOT PRESSURE THEORY



Root pressure is defined as hydrostatic pressure developed in the root due to accumulation of absorbed water. It the pressure exerted on the liquid contents of the cortical cells of the roots, under fully turgid condition this root pressure pushes the water up the xylem vessels to the aerial parts. It shows that water absorption is an active process.
Experiment on root pressure: The root pressure can be demonstrated in a plant by the following experiment.
Apparatus required: A well watered herbaceous plant, a knife, a rubber tube, a narrow glass tube and colored water.
Procedure: Water a potted herbaceous plant. Keep it over night. Next morning, cut off the stem a few centimeters above the soil level or near to the root. Fix a long and narrow glass tube to the cut end of the stump with the help of rubber tubing. Pour a little colored water in the glass tube and mark its level. The glass tube is connected to a manometer and whole setup is then left for observation.
Observation: After some time the level of the colored water rises in the tube. And rise in the level of the mercury of the manometer shows the measurement of root pressure.
Result and conclusion: A rise in the level of water in the glass tube is due to the pressure exerted by water exuded from the cut part of the stem.
The exuding of water from the cut end of the stem is called bleeding. The flow of water from the cut surface or bleeding when measured by mercury manometer is estimated to 3-5 atmospheres only.
                                                                                                                                                                                   mailto:bpokharel216@gmail.com?subject=Experiments                                                                                                                                            Demonstrated By:  Aditya and Bikash