Question

How many gaseous elements are there in the periodic table?

Answer 1

There are only some elements in the modern periodic table that are in the gaseous phase. Some of them are noble gases. And some belong to period $1,2{\text{ }}and{\text{ }}3$. The gases are way more different than solids and liquids. These molecules are larger than the other two. And their intermolecular distances are also high.

Complete answer:
The modern periodic table consists of many different types of elements. These different elements are metals, non-metals, and metalloids. Among them some are mostly solids, some are liquids and some are gaseous. The gaseous elements are present in the upper right corner on the right side of the periodic table. In total there are $11$ gaseous elements in the modern periodic table. These $11$ elements are:
Hydrogen (H), Helium (He), Nitrogen (N), Oxygen (O), Fluorine (F), Chlorine (Cl), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn), and Neon (Ne)
Among these $11$ gases, $6$of them are noble gases. They are Helium, Neon, Argon, Krypton, Xenon, and Radon.
The gases consist of large size molecules, and there are large distances between these molecules as compared to the other two states (solid and liquid). And so the gases are highly compressible. They also have low density compared to solids and liquids. They do not have a definite shape. The gases apply pressure in all directions.

Note:
Among all the gases, hydrogen is the lightest one. Fluorine is a dangerously powerful oxidant. Xenon is the rarest non-radioactive gas. There is one more gas named Oganesson (Og). This is a synthetically produced highly radioactive element. This is also a noble gas as predicted by various scientists.