Read: http://news.sciencemag.org/chemistry/2015/05/why-there-so-little-breathabl
ID: 923157 • Letter: R
Question
Read:
http://news.sciencemag.org/chemistry/2015/05/why-there-so-little-breathable-oxygen-space#disqus_thread
1. The article describes a new measurement that helps to explain an observation about interstellar space. In your own words, describe the observation, and how the new measurement helps explain this observation.
2. What is the difference between an oxygen atom and an oxygen molecule? Explain as if to a friend who is a non-science major.
3. The article offers a possible explanation for why molecular oxygen has been detected in the Orion Nebula, while not being detected in other interstellar regions. What is this possible explanation? What evidence could be gathered to support this explanation?
4. We learned about a method that could be used to detect the presence of atomic gases, such as hydrogen and helium in space. What is this method? Why wouldn’t this same method work to detect the presence of molecular oxygen (as opposed to oxygen that might be present as part of a water or silicate molecule)?
5. The binding energy holding oxygen to water ice and to silicate particles is given. Compare these values to the O=O bond energy in O2 of 498 kJ/mol. Given your comparison, would the process of atomic oxygen breaking away from dust particles and forming molecular oxygen be endothermic or exothermic?
Explanation / Answer
I'll answer question 1 to 3. The other two questions, try to do it yourself, the article it's not to difficult to understand. Try to analize it and think in the basis of science so you can know how to answer these 2 questions. If not, then post them in a new question thread:
1. The general onbservation that this article refers, is the fact that even though the scientist predict that after Hydrogen and Helium, the oxygen would become the third most common element in the universe, the fact is, that it's not. This is mainly because there aren't much evidence of molecular oxygen in the universe, and that's because the atoms of oxygen are, like, attached to stardust, preventing them from joining together again as molecules. How do they find out that? they did a ground experiment that measure the binding energy of oxygen atoms to stardust particles, in this case, water ice and silicates, responsibles of the interstellar grains, and prevent the atoms of oxygen to join together again as molecules. That's why there is such a few breathable air in space.
2. Let's see when we talk about atoms and molecules, we can actually talk as simply words. For example if I want to describe the word "piece", this word could be refering to anything, like a piece of cake. In this case, you are a taking "one" single piece of cake. One single stuff. But let's suppose that instead of taking one piece of cake, we take several "pieces" of cake. The word "pieces" is plurar and refer to more than one stuff, in this case, we can refer to more than one piece of cake (maybe two). With this analogy we can talk about the difference of an atom and a molecule of oxygen. an atom of oxygen is just one single atom or piece of oxygen. In the case of molecule of oxygen, we are talking about 2 or more atoms together or "pieces" of oxygen taking place. That's the difference between atom and molecule, (single and plurar).
3. The answer for this, I'm quoting a text from the article: "Oxygen atoms that float away from interstellar dust grains can join to make molecular oxygen. But when they stay stuck to the grains, hydrogen atoms combine with the oxygen to create water ice (H2O) instead. The water can then become part of asteroids, comets, and planets, setting the stage for the creation of life." This is why molecular oxygen it's not in other interstellar regions, and even in the orion nebula, it's a very little quantity compared to the quantity of hydrogen (1 million to 1 of oxygen). The reason would be that there is no enough interstellar dust in this region, compared to the interstellar dust of other regions in the universe, and that's why we can still fin some traces of molecular Oxygen in this regions.
Hope this helps.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.