Using only the periodic table, arrange each set of atoms in order of increasing radius: (b) S, Si, Sr

Video transcript

Hey everyone in this example, we need to recall our atomic radius trend on the periodic table and sort the given elements from largest to smallest size or atomic radius. So we're given argon a 17 and aluminum. And we're going to begin by recalling our trend for atomic radius, which we would recall will be increasing as we go towards the bottom left of our periodic tables. Now we want to go ahead and recall the locations for each of these given atoms on the periodic table. So beginning with Argon, we would recognize that it's located in group eight a. Which we recall is our noble gas group on our periodic tables and it's located across period three. And we would recognize that it has the atomic number given as 18 on our periodic tables. Now moving on to our next item, we have Aston time. So we should recognize that ascent een is located in Group seven A of our periodic tables across period seven. Or rather that should be period six of our periodic tables. And we would recognize that it has the atomic number 85. So it's much lower on the periodic table in comparison to argon because it's in period six and it has a much higher atomic number. So our last atom we have is aluminum. We should recall that aluminum has atomic number 13 is located in group three a of our periodic tables. And that is across period three as well. So, to begin our ordering from ascending order, since we want to start with the largest size of our atom here, we want to go ahead, we're going to look for the period number corresponding to the atom that is lowest on our periodic table because that would follow our trend for a higher atomic radius or an increased atomic radius. So what we would recognize is again our ascent een atom given is in period six. And so because that is lower on the periodic table, we should recognize that period six would lie somewhere around here. That is therefore going to be the largest atom or have the largest atomic radius. So we would go ahead and say that this would have a larger atomic radius than the next atom, which we would list which since are gone and aluminum are in the same period. We can't compare them by how low down they are on the periodic table. But we can compare them based on how far left they are on the periodic table because we would recognize that the further left we go on the periodic table would correspond to an increase in the atomic radius. And that would mean that going towards the right of our periodic table would give us a smaller atomic radius. And so we would recognize that argon is atomic number 18, whereas aluminum is atomic number 13. And so that means that aluminum comes before argon on the periodic table, meaning it's more towards the left of our periodic table in comparison to argon, which is more towards the right. And so that would mean that our atom, aluminum has a larger atomic radius. So we would go ahead and list it second in the ranking. And then that would leave us with argon last in our ranking for atomic radius. Because not only is it more towards the right, But it therefore has a smaller atomic radius compared to both aluminum and a 17. And so this would complete our ranking for the largest to smallest atomic radius of our given atoms. So this is our final answer. To complete this example. If you have any questions, please leave them down below. Otherwise, I will see everyone in the next practice video.