# Which of the following has the largest radius?

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B.
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In this new video, we’re going to take a look at atomic radius Now we’re going to say atomic radius is defined as half the distance between the nuclei in a molecule of two identical elements

What does that mean? Well, remember we know that we have an element which is represented by a sphere The diameter would just be the distance all the way across The radius is just half of that, so our atomic radius is just that And now if we are dealing a diatomic molecule we’d say that the sum of the radii equals the total distance between their two nuclei That’s what that definition is basically saying

Now we’re going to say it’s important to remember the trend for atomic radius So we’re going use this representation of the periodic table So, the best strategy here is just to make a sheet with all the trends because there are tons of different types of periodic trends that you need to remember one can be atomic radius So we’re going to say generally, atomic radius will decrease as we go from left to right across a period So it decreases going this way, and we going to say generally, it going to increase going down any group

So we going to say it increases going down this way So just remember that trend in terms of atomic radii