Question

Which is the bigger atom, argon or chlorine?

Answer 1

It is..........?

Explanation:

As a physical scientist, you should consult the data. See this [site.](https://en.wikipedia.org/wiki/Atomic_radius) The atomic radius of `Ar` is `71xx10^-12*m`; that of atomic chlorine is `79xx10^-12*m`. And this illustrates a general Periodic Trend: atomic size decreases across a Period from left to right as we face the Table; it INCREASES down a Group.

Incomplete electronic shells shield the nuclear charge very ineffectively, and this is certainly apparent with the given data.