Tuesday, December 2, 2014

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Top 20 facts about atoms

Top 50 facts about atoms

Atoms are tiny particles which build together to make every substance. An atom is the tiniest bit of any pure substance or chemical element. 

You could fit two billion atoms on the full stop after this sentence. 

The number of atoms in the Universe is about 10 followed by 80 zeros.

 Atoms are mostly empty space dotted with a few even tinier particles called subatomic particles.

 In the centre of each atom is a dense core, or nucleus, made from two kinds of particle: protons and neutrons. Protons have a positive electrical charge, and neutrons none.

 Both protons and neutrons are made from different combinations of quarks (see quarks).

 If an atom were the size of a sports arena, its nucleus would be just the size of a pea. 

Around the nucleus whizz even tinier, negatively-charged particles called electrons (see electrons).

 Atoms can be split but they are usually held together by three forces: the electrical attraction between positive protons and negative electrons, and the strong and weak ‘nuclear’ forces that hold the nucleus together.

 Every element is made from atoms with a certain number of protons in the nucleus.

 An iron atom has 26 protons, gold has 79. The number of protons is the atomic number. 

Atoms with the same number of protons but a different number of neutrons are called isotopes. 

The nucleus of an atom is made up of two kinds of particle: protons (red) and neutrons (green). 

Protons have a positive electric charge while neutrons have none. Tiny electrons (blue) whizz around the nucleus. In the 1890s scientists thought that atoms were solid like billiard balls and completely unbreakable.

 In 1897 J. J. Thomson discovered that atoms contained even smaller particles, which he called electrons (see electrons).

 In 1900 scientists thought atoms were like plum puddings with electrons like currants on the outside.

 In 1909 Ernest Rutherford was firing alpha particles (see radioactivity) at a sheet of gold foil. 

Most went straight through, but 1 in 8000 particles bounced back! Rutherford concluded that the atom was mostly empty space (which the alpha particles passed straight through) but had a tiny, dense nucleus at its centre. 
In 1919 Rutherford managed to split the nucleus of a nitrogen atom with alpha particles.

 Small atoms could be split. In 1932 James Chadwick found the nucleus contained two kinds of particle: protons and neutrons.

 In 1933 Italian Enrico Fermi bombarded the big atoms of uranium with neutrons. Fermi thought the new atoms that then formed had simply gained the neutrons.

 In 1939 German scientists Hahn and Strassman repeated Fermi’s experiment and found smaller atoms of barium. Austrian Lise Meitner realized that Hahn and Strassman had split the uranium atoms. 

This discovery opened the way to releasing nuclear energy by fission (see nuclear energy). 

Atoms are the building blocks of the Universe, the invisibly small particles from which matter is made. Atoms are so small that you could fit a billion on the full stop at the end of this sentence. 

Atoms are the very smallest identifiable piece of a chemical element (see elements). 

There are as many different atoms as elements. Atoms are mostly empty space dotted with tiny sub-atomic particles (subatomic is ‘smaller than an atom’).

 The core of an atom is a nucleus made of a cluster of two kinds of subatomic particle – protons and neutrons. 

Whizzing around the nucleus are even tinier particles called electrons. 

Electrons have a negative electrical charge, and protons have a positive charge, so electrons are held to the nucleus by electrical attraction.

 Under certain conditions atoms can be split into over 200 kinds of short-lived subatomic particle. The particles of the nucleus are made from various even tinier particles called quarks.
Publisher: Unknown - 5:06 AM

Monday, December 1, 2014

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top 7 interesting facts about Doctors

top 7 interesting facts about Doctors

Here is the top 5 interesting facts about Doctors : - 
1.        Doctor’s rigorous training ensures at a minimum a very high level of competency and professionalism.  Dr Mohammed Saed of Bradford England practiced as a doctor for over 30 years, during which time he prescribed creosote and suppositories to be taken orally, misdiagnosed everything from heart disease to a brain tumour the size of an orange. A whistle blowing pharmacist finally put an end to his practice (or should that practicing) when he prescribed cough medicine as a scalp tonic.

2.       Male doctors are best.  An analysis of almost 5,000 doctors and dentists referred to the National Clinical Assessment Service over the past eight years because of worries about their performance shows men outnumbering their female colleagues by 3-1.

3.       Older more experienced doctors are better than younger doctors. In a USA study of heart attack victims, mortality rates rose 1% for every two years since a patient’s doctor graduated from medical school.

4.       Doctors are poorly paid. The average salary for GPs is 110k, which compares well with that of a chartered accountant (senior) 100k, Architect 60k and lawyer 52k, and the glamorous newer profession of airplane pilot 63k.

5.       Doctors work long hours. A ‘journal of American medical  association’ study of 2008 saw the hours doctors work on average fell from 55 to 51 between 1996 2008, this fall in hours worked was not seen elsewhere in America professions or business ( which actually saw a rise in hours worked during that period)

6.       Young doctors are no less competent than their older colleagues. Some might think that newly trained doctors would bring many benefits with them. Fresh from medical school, highly motivated, full of enthusiasm, up to date with the latest medical techniques,  and above all well supervised ( therefore less prone to error) . In fact according to an Imperial College London study, newly trained doctors hitting the wards in august cause an 8% rise in mortality.

7.       Doctors are good for you. A persistent but puzzling fact first identified in 1978, the more doctors in a given community the higher the mortality rate. This statistical fact was confirmed by a truly monumental study (Cornel University 2001) which included; 47 Japanese prefectures, all 3,000 + counties of the USA, and 29 (mostly) European countries. The bad news was it found the more doctors in your community the more likely you were to die (the good news ,if you can call it that, was this increased mortality rate was due to a complex combination of factors, many of the centred on the deleterious effects of urban living and not the lethality of doctors).
Publisher: Unknown - 1:13 PM

Friday, September 19, 2014

5 interesting facts about tsunami

5 interesting facts about tsunami

1-A tsunami occurred in Alaska in 1958 that was 524 metres (1,719 feet) tall – even taller than the
Empire State Building.
2-A tsunami is a massive wave that sweeps over the land and destroys everything in its path. It can be 30 metres (100 feet) high when it strikes the shore.
3-Mount Fuji, the volcano that towers over the Japanese capital Tokyo, last erupted in 1707.The earthquakes and tsunami that followed killed 30,000 people and the rice fields were left barren for 100 years.
4- A tsunami can travel across the ocean as fast as a jet plane, at speeds of up to 750 kilometres (465 miles) per hour.
5-In 2004, the tsunami in the Indian Ocean killed around 230,000 people and was the ninth deadliest natural disaster since the Middle Ages.
6-A tsunami occurred in Alaska in 1958 that was 524 metres (1,719 feet) tall – even taller than the Empire State Building
Publisher: Unknown - 2:47 PM

4 facts about canada

1-A giant squid washed up in Canada in 1878 had a body that was 6 metres (20 feet) long with tentacles that measured up to 10.7 metres (35 feet) long.
2-The expression ‘once in a blue moon’ means that something hardly ever happens.A blue moon does happen occasionally, though – It happened in 1950 when a large wildfire in Canada sent soot high up into the sky making the moon look blue.
3-A field of fescue grass, which grows in Canada, looks like lots of little plants, but is really a single plant that’s hundreds of years old.
4-Tornado Alley is an area in the USA from central Texas to the border of Canada that has the perfect weather conditions for tornadoes.
Publisher: Unknown - 2:41 PM

Thursday, September 18, 2014