So at standard room temperature we have 25 degrees Celsius, and at standard pressure we have what's called one atmosphere. Atmosphere is just ah, unit for pressure. We'll go in greater detail on that particular unit for pressure. When we get to a chapter on gas is but just realize here, when we say standard room temperature and standard pressure, it's 25 degrees Celsius and one atmosphere. Now, under these conditions, the elements can exist under three states of matter, so we know we have solids, liquids and gasses when it comes to solids, solids. If we look here on the left side, you can see that in this image, all of our atoms are neatly packed next to each other tightly. That's because solids maintain a fixed shape and volume. Yeah, liquids. On the other hand, we can see here in this image of the liquid, all of them are not locked in grid like they were in a solid and the arrows. You show that the atoms move in random directions. They're still in contact with one another, but they're kind of unpredictable with their movements. That's because liquids can conform to the shape of a container, but not the volume. So, for instance, let's say you had a container that can hold 25 mL of liquid, but you on Lee had 10 mL of liquid. Yes, the liquid itself would conform to the shape of the container, but it wouldn't be able to fill it up because there's not enough of it. And that's what's going on with this liquid. They basically spread out as much as they can, but they can't take up the volume if there's not enough of it. Finally, gasses for gas is we can see here that the gas is these atoms over here on the right are even Mawr spread apart from one another. That's because gasses have total freedom and liberation from one another. They're moving around even mawr randomly than liquids. So we're gonna stay here. That gas is, they assume both the shape and volume of a container. So no matter how large your container gasses will spread around enough to take up every square inch off the container. Now, if we're looking at the elements of the periodic table, we can see that a vast majority of them are shaded in black and gray. so a vast majority of our elements mawr under standard room temperature and pressure will exist as a solid. We can see that when it comes to liquids, there's only really two liquids under those conditions and that be mercury and bro meat. And then when it comes to gas, is there's quite a few gas is so we have hydrogen. We have nitrogen, oxygen, flooring, chlorine. And then the last group is pretty easy to remember that there the gas is because they're called the noble gasses, right? So the name gives it away. So the name of Group eight A are the noble gasses. Now you might also notice that from our F toe o. G. They're not shaded in any color. That's because those elements majority of them have been synthesized in the lab. And because they're so loud, low down on the periodic table, their masses incredibly great, this leads to their high instability. Okay, so they're not very stable, and because of that, it's hard to really pinpoint the exact phase. They would exist under 25 degrees Celsius and one atmosphere, so as a result, we just say that they don't have a face under those temperature and pressure conditions. All right, so just remember, when it comes to our three phases of matter, what the temperature and pressure conditions that each one of these elements exist. This is key to answering certain questions when it comes to the arrangement and the presence of an element. So now that we've looked at the periodic table on its phases, let's move on to some questions.