Periodicity in Period Three Poem

Argon doesn't have one as

It doesn't make bonds, though,

Electronegativity increases,

As across period 3 we go.

The number of protons increases,

Which ups the positive charge.

So electronegativity changes from,

Quite small up to large.

Atomic radius decreases,

As you go from left to right.

But Argon doesn't make bonds,

So doesn't have one – try…