Step-by-step explanation:
Argon has an atomic number of 18, while neon has an atomic number of 10.
The atomic radius is comprised of the atom’s nucleus and electron cloud. As you go down on the periodic table, the effective nuclear charge decreases. This results in more screening of the electrons
from the nucleus (decreasing the attraction between the nucleus and the electrons) resulting in a larger atomic radius.
However, because they’re both noble gasses, the size difference in this case can be easier described by the number of particles in each atom.
Argon has 18 protons, 18 electrons and 22 neutrons.
Neon has 10 protons, 10 electrons and 10 neutrons.As you can see, argon has more “stuff.”
The increase in protons and electrons in particular results in a larger electron cloud, which means a much larger atomic radius than in neon.
i hope it helps u :)