字幕表 動画を再生する 英語字幕をプリント When you drink water, you’re drinking the most abundant element in the universe, but what’s really going on with Hydrogen? Hey guys, Amy here for DNews. You might not think about it in such scientific terms, but you consume a lot of hydrogen, and you’re even made of hydrogen! Which is less creepy than it sounds; you’re not unknowingly a cyborg or anything. Hydrogen is the simplest element with just one proton orbiting its nucleus, a simplistic arrangement that allows it to hold the top spot on the periodic table of the elements. It’s also the most abundant element in the universe with helium coming in at a distant second. When the Universe was a fraction of a second old, immediately after the Big Bang, it was about 92% hydrogen atoms and 8% helium atoms by number which is roughly three-quarters hydrogen by mass with trace amounts of other elements. As the universe cooled, these early atoms stabilized and cooled into gas clouds that eventually clumped together to form protostars. Those protostars got massive enough to develop their own gravity, drawing other material into them, adding mass, pressure, and heat until hydrogen atoms are able to fuse together to form helium. These became stars, the fusion reaction making them bright. Heavier elements are also formed inside stars, and when stars die and explode, they send those heavier materials spewing throughout the universe where they were eventually incorporated into new stars and protoplanets that became bodies like our Earth. So all those elements that are in stars are in our planet as well, but not in the same amounts. Hydrogen might be the most abundant element in the universe but it’s pretty rare on Earth. The name hydrogen comes from the Greek hydro meaning "water" and genes meaning "forming," so its existence is linked to water as you might expect; It’s the H in H20. But though [a][b]the cells that make up our body have a high amount of water, hydrogen only makes up less than 10 percent of the material in the carbon-based human body and less than 0.15 percent of the material that makes up the Earth! Our planet is rich in oxygen, nitrogen — which are the most abundant elements in our atmosphere — and silicates, which make up the bulk of the material in the crust. Hydrogen is largely found in compounds like water, and what hydrogen that does reach the Earth doesn’t stick around; it escapes pretty quickly from the atmosphere. The Earth’s gravity just can’t hold on to it. But it’s immensely useful. Hydrogen is used in rocket fuel, welding, the production of hydrochloric acid, and reducing metallic ores. And as a fuel, it’s a clean fuel. Hydrogen carries energy without carbon in it, so when it burns it produces water as a byproduct. But there’s a chance we could get hydrogen from elsewhere, namely off the planet, and use it. Companies like Planetary Resources are looking at mining asteroids not for precious metals but for elements like hydrogen that could be used to make fuel, literally fueling space exploration and potentially vehicles on Earth as well. If you want a basic breakdown of hydrogen, check out this video from our brand new show TestTube 101! So what do you guys think about hydrogen as a clean fuel. Is it worth tapping into the literal universal stores? Let us know in the comments below! Or let us know on Twitter @DNews, and I’m on there as well as @astVitnageSpace. And of course, for more DNews every single day of the week, don’t forget to subscribe!
B2 中上級 水素はどこから来るのか? (Where Does Hydrogen Come From?) 57 10 songwen8778 に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語