Last week we brought you ten science and technology “firsts” enabled by mighty hydrogen. This week we follow up with another list: five interesting facts that may defy your commonly held beliefs about the simplest of all atoms. Hydrogen is full of surprises because it behaves like no other element in the universe. You can find it furiously burning in stars, gently holding the molecules of life together, or not find it at all—although it is practically everywhere.
Close-up on the Sun’s hydrogen flares. Solar Dynamics Observatory, NASA. Creative Commons Licensing.
Here are five curious facts about hydrogen that I find intriguing and worth noting in this week’s post.
It sits in the number one position in the Periodic Table. Its atomic number of one means it has one single proton in its nucleus. Yet, this number one position is deceiving: it took us thousands of years to discover hydrogen. It is hard to imagine, but 18 other elements were identified before we detected the most abundant of them all. Here is an interesting timeline of the elements discovered before hydrogen. Copper, lead, gold, silver, iron, carbon, tin, sulfur, mercury, zinc, arsenic, and antimony were all unearthed in antiquity. This is not surprising, as most of these elements are solid and can be easily found in nature in their pure form. As civilization made progress, more elements were found as humans extracted them from their natural states. This was the case for the next six elements—all discovered after the 16th century: phosphorous, cobalt, platinum, nickel, bismuth, and magnesium. The time for hydrogen came in 1766 when Henry Cavendish was the first to isolate and characterize hydrogen as a discrete substance, naming the gas “flammable air.” It was not until 15 years later that he discerned that when hydrogen burned, it combined with oxygen to produce water. Cavendish realized that he had, in fact, discovered an element, not just a substance.
We all studied it in school: a diagram with a single spherical proton forming the nucleus and a lone electron describing the orbit around it. No neutron. Like a one-planet solar system, the hydrogen atom is elegant and simple. It is, in fact, this elegant simplicity (and lack of neutron) that sets it apart, making hydrogen the go-to element that scientists have used for centuries to understand the subatomic world. Yet, not all hydrogen is created equal. In 1910, British radiochemist Frederick Soddy discovered isotopes while observing the natural process of radiation that occurs in all elements. He noted that this process could lead to atoms that differed in their weights (the number of protons and neutrons that form the nucleus of the atom) but were chemically identical. Soddy worked with hydrogen and discovered Deuterium, which is an isotope of hydrogen that has a neutron (and is also called heavy hydrogen). The most common form of hydrogen (H1) has one proton in the nucleus and one electron orbiting around it. In its rare form, Deuterium (H2) has three particles: one proton, one electron, and one neutron. Deuterium occurs naturally, comprising 0.015% of all hydrogen in the universe. Interestingly, the existence of deuterium at a low, but constant, primordial fraction in all hydrogen matter is one of the main arguments in favor of the Big Bang theory.
Water is essential to life as we know it. When we search for life elsewhere, we follow the water. Dozens of space probes have been launched after the discovery of water on Mars and several of the moons orbiting Jupiter and Saturn. Here on Earth, scientists believe life started when a mix of primordial amino acids in water was ‘ignited’ by some electrochemical reaction. From that moment, all life on our planet uses water. Since every water molecule has two atoms of hydrogen for every one atom of oxygen, it follows that hydrogen is necessary for life. However, hydrogen plays another equally crucial role in supporting life, literally. Hydrogen is essential to DNA. The molecule’s double helix structure is held together by hydrogen bonds. Specifically, the two strands of DNA stay together by hydrogen bonds that occur between complementary nucleotide base pairs. Two hydrogen bonds occur between the adenosine and the thymine base pairs; and between the cytosine and the guanine base pairs, there are three hydrogen bonds. Without these hydrogen bonds that glue the molecule’s two arms together, there would be no double helix; and without it, no life.
In a sense, the hydrogen economy is already here: you may unknowingly use hydrogen to power everything—from your home to your car. This is true whether you use traditional or alternative energy, whether you have a gas-hungry Hummer or an electric Nissan Leaf, and whether you have solar panels on your roof or use the grid. It all starts at the center of the sun. The sun’s nuclear fires convert hydrogen to helium, releasing energy in the form of photons that arrive here in just eight minutes. Millions of years ago, these photons were used by ancient plants for photosynthesis. Dinosaurs and other organisms fed from these plants, and as they died, their carbon remains combined with water and decomposed into the hydrocarbons (oil, coal, and natural gas) that power our cars and factories today. If these photons hit your solar panel, it was hydrogen that produced them in the first place. The same is true for the electricity that charges electric cars and appliances: it is either produced by water in dams (H2O), produced using turbines powered by gasoline or natural gas (hydrocarbons), or produced in a nuclear reactor whose fuel was manufactured when hydrogen made its magic at the center of most stars. This ever-present, mighty element holds the potential to go even further—to power our society on its own, as hydrogen fuel, in a clean and sustainable way.
A couple of months ago, Scientific American ran an interesting article entitled, “The Race to Turn Gassy Hydrogen into Solid Metal.” The article explored some of the unconventional properties that metallic hydrogen would have if it could be produced in the lab. Pure hydrogen is a gas. To make it a liquid, high pressure and super cold temperatures are required; that is why it is so costly to store and transport. To make hydrogen metallic would require enormous pressures—similar to the pressures found at the center of stars—which is the only place where hydrogen is believed to be metallic. The article explains how several science teams are beginning to explore the use of diamonds and lasers to apply the pressures required. So far, they’ve been able to replicate the pressures at the center of planets, but they have a ways to go before we can see metallic hydrogen in the form of a superfluid. This superfluid metal would have some intriguing properties. For starters, as the article states, “If metallic hydrogen is a superfluid, researchers may have a material on their hands that defies understanding. All of the superconductors that we know [of] are solid … and all superfluids are insulators. This liquid hydrogen would be a superconductor and superfluid at the same time—nothing like this has ever been observed.” There is also scientific speculation that the other unconventional property of this superfluid would “defy gravity” but that would take us into the realm of pure speculation. So, let’s just leave metallic hydrogen as a superconducting fluid, which is quite impressive, and unique, on its own.
Since its first observation by Swiss alchemist Paracelsus in 1536, hydrogen has intrigued and surprised scientists for almost 500 years. The “essential element” as American physicist and author John Rigden called it, continuously defies our working assumptions, challenging science to dig further to advance our understanding of the inner workings of the natural world. The number one element not only allows us to see far into the cosmos and deep into our own DNA, but it also has the potential to become the clean and abundant source of energy that could help us tackle the pressing sustainability issue we face today.
As the Hydrogen 2.0 ecosystem gains momentum, we’ll be sharing our views and insights on the new Hydrogen 2.0 Economy. We also update our blog every week with insightful and current knowledge in this growing energy field.