Helium how many protons

The number of protons is the atomic number , and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons. For helium, it is 4: two protons and two neutrons. For most of the 16 lightest elements up to oxygen the number of neutrons is equal to the number of protons. For most of the remaining elements, there are more neutrons than protons, because extra neutrons are needed to keep the nucleus together by overcoming the mutual repulsion of the increasing numbers of protons concentrated in a very small space.

For example, silicon has 14 protons and 14 neutrons. Its atomic number is 14 and its atomic mass is The most common isotope of uranium has 92 protons and neutrons. The dot in the middle is the nucleus, and the surrounding cloud represents where the two electrons might be at any time.

The darker the shade, the more likely that an electron will be there. The helium is formed during the natural radioactive decay of elements such as uranium and thorium. These heavy elements were formed before the earth but they are not stable and very slowly, they decay. One mode of decay for uranium is to emit an alpha-particle.

This alpha-particle is actually just the heart of a helium atom - its nucleus. Once it has grabbed a couple of electrons, a helium atom has been born. This decay process for uranium is incredibly slow; the time it takes a given quantity of uranium to halve, its so-called half-life, is comparable to the age of the earth. This means that helium has been continuously generated ever since the earth was formed.

Some of the gas might eventually creep through the earth and escape into the atmosphere; fortunately, when conditions are right, some is trapped underground and can be harvested for our use. The situation is very different in space. The remaining one percent is made up of all the heavier elements.

In the high temperatures of the sun, the hydrogen nuclei are fused together to eventually form helium. This fusion process, whereby heavier atoms are made from lighter ones, liberates vast amounts of energy. Recreating the process on earth may be the answer to our energy problems in the future.

Since helium makes up about a quarter of the mass of the sun, it is not surprising that its presence was detected there over years ago. What is perhaps surprising, is that helium was discovered in space 26 years before it was found on earth. It has been known for hundreds of years that certain elements impart characteristic colours to a flame - a fact crucial to the coloured fireworks that we enjoy.

Copper, for example, gives a green colour, whereas sodium gives a yellow colour. It is actually possible to identify elements by the careful examination of such coloured flames. The light is split up into a spectrum using a prism or diffraction grating in an instrument called a spectroscope. Rather than seeing a continuous rainbow of colours, a series of sharp coloured lines is formed. This series of lines is characteristic of the particular element and acts as a sort of fingerprint.

In the 19th century, scientists turned their spectroscopes to the sun and began to detect certain metals there, including sodium, magnesium, calcium and iron. In two astronomers, Janssen and Lockyer, independently noticed some very clear lines in the solar spectrum that did not match up to any known metals. While other astronomers of the time were unsure, Lockyer suggested these unidentified lines belonged to a new metal which he named Helium after the Greek personification of the sun, Helios.

For over 20 years, no sign of the metal helium was detected on earth and Lockyer began to be mocked for his mythical element. However, in the chemist William Ramsay detected helium in the gas given out when a radioactive mineral of uranium was treated with acid. The helium formed from the radioactive decay had been trapped in the rock but liberated when the rock was dissolved away in the acid.

Finally Lockyer's element had been discovered on earth, but it was no metal, rather an extremely unreactive gas. To this day, helium remains the only non-metal whose name ends with the suffix -ium, an ending otherwise exclusively reserved for metals. Aside from being used to fill balloons, both for our entertainment, and for more serious purposes, such as for weather balloons, helium is used in other applications which depend on its unique properties.

Being so light, and yet totally chemically inert, helium can be mixed with oxygen in order to make breathing easier. This mixture, known as heliox, can help save new-born babies with breathing problems, or help underwater divers safely reach the depths of the oceans.

At minus degrees centigrade, liquid helium has the lowest boiling point of any substance. Because of this, it is used to provide the low temperatures needed for superconducting magnets, such as those used in most MRI scanners in hospitals. In many facilities where helium is used, it is captured and reused.

If it isn't, it escapes into the air. But it doesn't simply accumulate in the atmosphere. Helium is so light that it can escape the pull of the earth's gravitational field and leave our planet forever. This is the fate of the helium in our balloons. Whereas it may be possible to reclaim and recycle other elements that we have used and discarded, when we waste helium, it is lost for good.

In years time, people will look back with disbelief that we wasted this precious, unique element by filling up party balloons. Cambridge University's Peter Wothers telling us the tale of element number two, Helium. Next time we're off to 18 th century Scotland and an element that was the wrong colour.

In , an intriguing mineral came to Edinburgh from a Lead mine in a small village on the shores of Loch Sunart, Argyll. At that time, the stuff was thought to be some sort of Barium compound. Other chemists, such as Edinburgh's Thomas Hope later prepared a number of compounds with the element, noting that it caused the candle's flame to burn red, while Barium compounds gave a green colour.

And that's because it wasn't Barium at all, it was Strontium and Richard Van Noorden will be here to explain how, amongst other things, it's shown us that Roman gladiators weren't meat eaters they were in fact vegetarians. That's next week's Chemistry in its Element and I hope you can join us. I'm Chris Smith, thank you for listening and goodbye. Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists.

There's more information and other episodes of Chemistry in its element on our website at chemistryworld. Click here to view videos about Helium. View videos about. Help Text. Learn Chemistry : Your single route to hundreds of free-to-access chemistry teaching resources.

We hope that you enjoy your visit to this Site. We welcome your feedback. Data W. Haynes, ed. Version 1. Coursey, D. Schwab, J. Tsai, and R. Dragoset, Atomic Weights and Isotopic Compositions version 4. Periodic Table of Videos , accessed December Podcasts Produced by The Naked Scientists. Download our free Periodic Table app for mobile phones and tablets. Explore all elements. D Dysprosium Dubnium Darmstadtium.

E Europium Erbium Einsteinium. F Fluorine Francium Fermium Flerovium. G Gallium Germanium Gadolinium Gold. I Iron Indium Iodine Iridium. K Krypton. O Oxygen Osmium Oganesson. U Uranium. V Vanadium. X Xenon. Y Yttrium Ytterbium. Z Zinc Zirconium. Membership Become a member Connect with others Supporting individuals Supporting organisations Manage my membership.

Facebook Twitter LinkedIn Youtube. Discovery date. Discovered by. Origin of the name. Because it is so light, helium does not stay in the atmosphere — it escapes into outer space! There are helium reserves underground.

Terrestrial helium is created by radioactive decay and becomes trapped with other natural gases. When the gases are extracted from the ground, the helium is separated from the rest of the gases. During the first half of the 20th century, helium was quite scarce. The United States had significant reserves but banned exports to other countries. Helium is a stable gas, so it is much safer to use than hydrogen, which is reactive and highly flammable. The export ban meant other airships such as the Hindenburg were forced to use hydrogen as the lifting gas.

Commercial airship travel ceased after the Hindenburg caught fire in mid-air. At low temperatures, helium becomes a liquid and is very useful as a coolant.

Liquid helium cools the magnetic coils of MRI scanners in hospitals, the electromagnets in the Large Hadron Collider, satellite instruments and rocket fuel. We encounter helium quite often in our daily lives — in party balloons and in some of the lasers used to scan merchandise in grocery and retail stores. One time we hope to avoid using helium is when we are in the car — it fills the airbags in the event of a crash.

When helium is cooled to near absolute zero, it becomes a superfluid — a state of matter unique to liquid helium. The superfluid has an apparently frictionless flow. It can also move along a surface, travelling upwards against the force of gravity.

The speed of sound in helium is about three times the speed of sound in the air.