Recognition 1 | Science passage | The Sun

- [Instructor] The passage provides enough information to answer which one of the following questions? Okay, so... So four of these things, we're not gonna be able to answer with the information with the passage. And one of them, the answer will be in the passage. So this is really a question of how much we remembered, but if we need to go back to the passage, we can. Okay. A, does the iron content of Earth exceed 50% of its total mass? I don't know if they said how much iron is in Earth. I don't remember them seeing a number. So this kind of makes me think that that probably we don't know the answer to this. We can look for a little bit later. B, who first proved that the sun generates heat from hydrogen by nuclear fusion? Um, I don't think they told us that. We know that Einstein was involved in like the prove event, but we don't, we don't-- it wasn't about the proof of that. C, do any objects in the solar system other than the Earth and the sun contain iron? Ah yes, I believe that that was mentioned so let's-- They mentioned asteroids, I think. But we can go on back and make sure about that. What percentage of the sun's mass is composed of iron? Let's see. They definitely mentioned that there's iron in the sun. So we can look for that in a minute. Can the fusion of atoms other than hydrogen atoms produce energy? There was no talk of other kinds of fusion. So that's definitely out. We can just get rid of this choice, and get rid of this choice. And now what we can do is we can, you know, look for these other ideas. Does the iron content of Earth exceed 50% of its total mass? Let's have a look this passage. Okay, so... Let's see where we are. Hydrogen and helium, okay. Let's start. We're looking for iron. Orthodox view that the sun was mainly iron, was buttressed by the knowledge of Earth, Earth and all known asteroids. All known asteroids contain iron. So there's our answer. They also don't know exactly how much iron is in Earth. That wasn't mentioned. So we can definitely cross out this one. And we didn't know exactly how much there was there. So we have our answer. Asteroids.