How Small is an Atom?

Kurzgesagt - In a Nutshell

Transcript:

Atoms are ridiculous and unbelievably small. A single human hair is about as thick as 500,000 carbon atoms stacked over each other. Look at your fist, it contains trillions and trillions of atoms. If one atom in it were about as big as a marble, how big would your fist be? Well… about the size of Earth. Hm… still hard to imagine? Let’s try something different.

Look at your little finger. Imagine that its tip is as big as the room you’re sitting in right now. Now fill the room with grains of rice. One rice corn represents one cell of your fingertip. Now let’s zoom in on the rice corn. And now, one cell is as big as the room you’re in right now. Let’s fill it with rice again. This is about the size of a protein. And now, let us fill all the empty spaces between the rice corns with fine grains of sand. This is roughly how small atoms are. What is an atom made of? 

Let us just pretend that atoms look like this for a minute to make it easier to understand. An atom consists of three elementary particles: neutrons, protons and electrons. Protons and neutrons bind together and form the atom core, held together by the strong interaction, one of the four fundamental forces in the universe. They are made from quarks and held together by gluons. Nobody knows exactly how small quarks are. We think they might literally be points, like in geometry. Try to imagine them as being zero-dimensional. We suspect that quarks and electrons are the most fundamental components of matter in the universe.

Electrons orbit the atom core. They travel at a speed of about 2,200 km/s, fast enough to get around the Earth in just over 18 seconds. Like quarks, we think electrons are fundamental particles. 99.999999999999% of an atom’s volume is just empty space… Except that it isn’t. What we perceive as emptiness is actually a space filled by quantum fluctuations, fields that have potential energy and build and dissolve spontaneously. These fluctuations have a fundamental impact on how charged particles interact. How much space do the core and electrons actually fill? If you were to subtract all the spaces between the atom cores from the Empire State Building, it would be about as big as a rice corn. All the atoms of humanity would fit in a teaspoon. There are extreme objects where states like this actually exist. In a neutron star, atom cores are compacted so densely that the mass of three Suns fits into an object only a few kilometres wide. By the way, what do atoms look like? Well, kind of like this. 

Electrons are like a wave function and a particle at the same time. We can calculate where an electron might be at any given moment in time. These clouds of probability, called orbitals, are where electrons might be with a certainty of 95%. The probability of finding an electron approaches 0 the further we get away from the atom core, but it actually never is zero, which means that, in theory, the electron of an atom could be on the other side of the universe. 

Okay, wait a second. These strange thingies make up all the matter in the universe. For many dozens of known elements, you don’t need many dozens of elementary particles, just three. Take one proton and one electron, and you have hydrogen. Add a proton and a neutron, you have helium. Add a few more, you get carbon, a few more, fluorine, even more, gold, and so on. And every atom of an element is the same: all hydrogen atoms in the universe, for example, are the same. 

The hydrogen in your body is exactly the same as the hydrogen in the Sun. 

What's inside an Atom?

In the early 1900’s, the atom was considered the ultimate, indestructible unit of matter. They believed, atoms of the then known elements, such as oxygen, nitrogen, hydrogen and others, could not be broken down into anything simpler. But later, certain experiments like ionic dissociation and the cathode ray tube, indicated the existence of subatomic particles. These and other experiments lead to the knowledge of the proton, electron and neutron as the basic subatomic particles.

Proton: charge = +1, mass = 1.67 x 10^-24 kg

Electron: charge = -1, mass = 9.11 x 10^-27 kg

Neutron: charge = 0, mass = 1.67 x 10^-24 kg

Physicists thus have discovered that atoms are not solid and that electrons rotate around the nucleus and complex orbits. But the understanding of atoms stopped with the electrons, protons and neutrons? The answer is No. 

Modern physics examines particles at the sub-atomic level. Some of the smallest particles are called Quarks. Quark Theory has been around since the mid-nineteen sixties. But a Quark has never been isolated. No one has ever seen a Quark. So you might ask how do scientists know they exist? The answer comes from data collected at high-energy particle accelerators.  Particles are accelerated to nearly the speed of light around the long distant underground tract and smashed together. By studying the patterns made by the new particles that are created in the collisions, scientists are able to determine the properties of the particles and their interactions. The tests have been repeated and the results have been duplicated with enough experiments to convince us that quirks are real and just as fundamental today, as the familiar electron, proton and neutron, were once thought to be. Quarks come in three paired types, that physicists call flavours. They are,

Up and Down

Charm and Strange 

Top and Bottom

Up and down were named based on components of their spin. Strange quarks were given the name, strange because they were observed in particle decays that had slightly longer lifetimes than they should have done. The charm quark was given the name because of it's fascination. The way that it fascinated the physicists at the time. Bottom and Top quarks were chosen by a famous physicist named Haim Harari. He chose the names because they were the logical counterparts of the up and down quark. 

These Quarks are bind together with the help of Gluons. Gluons are hypothetical massless subatomic particle, believed to transmit the force binding the quarks together in a hadron. Gluons mediate the strong force. They have no mass and no electric charge.

Everything you need to know about the newly discovered Elements

Img Credits : wired.co.uk

The International Union of Pure and Applied Chemistry (IUPAC) announced that four new elements will be joining the other 114 on the periodic table of elements. The addition of elements 113, 115, 117 and 118 means, the seventh row or period is now complete! They still don’t have proper names yet, they’re just called by their numbers. So where did these as yet unnamed elements come from? Scientists from Lawrence Livermore National laboratory in California and the Riken institute in Japan, smashed atoms together in particle accelerators and these new elements were created when the two nuclei fused. But the new elements existed only for a fraction of a second. Then they decayed into isotopes of other elements.

Element 113, the one created in Japan, exists for less than a thousandth of a second before it decays into other isotopes, so it’s unlikely you’ll run into this element anytime soon. So alright, sweet new elements. While cool, it probably won’t mean much for your daily life, yet. Unless you have to memorise the entire table in chemistry class, sorry 10th graders. But for science, it could be huge. Scientists have been searching for the elusive “Island of Stability," which according to a theory by Nobel laureate Glenn Seaborg is a stable element with just the right number of protons and neutrons. And these new elements might be getting scientists closer to the island of stability.

Img Credits : iflscience.com

You see, most heavy elements, ones with more than 113 protons like these new ones, only exist for a short amount of time. That’s because the force of the positive charges of their protons is too strong and the nucleus is pushed and pulled apart in a fraction of a second. But just like atoms become stable when their outer electron shells are full, some researchers, like Seaborg, believe that if a nuclei has a certain number of proteins arranged in just the right way, the element would be stable, it could last. If we can create this theoretical stable element it could be used to build things we haven’t even imagined yet! Even the effort of doing so, teaches scientists "a tremendous amount of just basic nuclear physics." According to Seaborg, the magic number to hit is 114 protons and 184 neutrons. 

And after  years of trying, Seaborg’s mentee Ken Moody finally hit the sweet spot by slamming together plutonium and calcium which briefly created a new element. Unfortunately, while the element, now called flerovium, or Fl has 114 protons it doesn’t have the needed 184 neutrons, and so it fell apart too quickly. Element 117, has been heralded as a possible “shore to the island of stability”. Five years ago, A U.S.–Russian team first created it at the Joint Institute for Nuclear Research in Dubna, Russia. Described in a journal Physical Review Letters, this new element has a half-life of about 50-thousandths of a second. Which means in that short of a time, half the element will decay into other isotopes like lawrencium-266, which had 103 protons and 163 neutrons, a combination never seen before. This lawrencium-266 even lasted a long time for an isotope, with a half life of 11 hours. Because of this, one of the lead authors said “Perhaps we are at the shore of the island of stability.” 

So, maybe, science is one step closer to creating a new element which we could use in ways we haven’t even dreamed of. And though we’re not there yet… we’re getting closer. It’s clear more research is needed. There’s no theoretical limit to how big elements can get! One day scientists might just start filling out the elusive 8th row! So don’t change your shower curtain just yet.

Credits : DNews