‘Exploring the elements: Hydrogen’ by Clara MacCarald
1. Without hydrogen there would be no stars in the night sky and no sunshine. Hydrogen is considered one of the building blocks of life.
2. Hydrogen is odourless, colourless and has no taste.
3. Hydrogen, the lightest element, has the smallest atomic weight. It is the first element listed in the first periodic table ever published.
4. Hydrogen makes up 93% of all atoms in the entire universe. Large amounts of hydrogen can be found floating in space, on Earth, on other planets, and in stars. In fact, stars such as the sun shine because they contain massive amounts of burning hydrogen.
5. On Earth, hydrogen is usually found with its buddy oxygen in the form of water in lakes, streams, seas and oceans.
6. Boiling water cannot separate hydrogen from oxygen. It only creates steam, the gaseous form of water. However, electrolysis can turn water into hydrogen. During electrolysis, an electric current through water will break the bonds between hydrogen and oxygen, separating the two elements.
7. Other ways to release hydrogen include the breakdown of organic matter by microbes, the action of sodium or potassium hydroxide on aluminum, and the release of hydrogen from acids by certain metals.
8. Acidic liquids have an excess amount of hydrogen ions (hydrogen atoms that lose their electrons). Rather than floating freely, the ions bond with water molecules to make H3O+. The acidic bite of lemon juice or vinegar may be the closest we can get to tasting hydrogen.
9. Tritium, an isotope of hydrogen with two neutrons is unstable. Subatomic particles are spontaneously emitted from tritium atoms, called ionizing radiation. The radiation can knock electrons away from other atoms, causing damage to living cells and cancer.
10. Artificial and natural processes put tritium into atmosphere. It can combine with oxygen to reach Earth through radioactive rain. However, tritium atoms decay quickly and do not accumulate. So there’s no need to worry if you get caught outside in the rain.
11. Hydrogen sulphide (H2S) is flammable, smells like rotten eggs, and occurs in mineral waters, volcanic gases and decaying matter. In fact, the bacteria that break down undigestible food in your large intestine can create hydrogen sulphide gas, which we expel as flatulence.
12. Hydrogen cyanide (HCN) can be used to make plastic. Burning the plastic can release the poison into the air along with a host of other nasty toxins.
13. When four hydrogen atoms bang into each other, they will fuse together to form a single helium atom. These collisions and the subsequent joining together of elements are called fusion. Hydrogen has one proton per atom, but helium has two. The extra mass becomes a lot of energy.
14. Fusion offers the potential to create vast amounts with virtually no pollution, but we may never realize this potential. A fusion plant would need to heat hydrogen and helium atoms to hundreds of millions of degrees. To be successful, the plant would need to produce more energy with fusion that it used getting to the right temperature.
15. The National Aeronautics and Space Administration has used liquid hydrogen for decades as a rocket fuel. Liquids take up much less space than gas. As the lightest element, liquid hydrogen gives the biggest bang per pound of any other rocket fuel.
16. Theoretically, cars and other vehicles could use liquid hydrogen, except that storage is a big challenge. If the fuel heats up, its rapid expansion into a gas could cause an explosion.
17. Liquid hydrogen is used in cryonics, which is the study of the effects of very cold temperatures. Cryopreservation is the process of freezing and preserving organs for potential future transplant.
過去兩星期在粉嶺樓路工作, 午飯時我都會去聯和墟附近吃, 剛巧粉嶺圖書館就在旁邊。有時, 我會趁著放飯的一個多小時爭取時間看看書。在這兩星期, 小弟會上載遇到的美麗圖畫。