Question

How many mono atomic elements are there ??? Name them??

Answer 1

Monatomic elements are simply elements that are stable as single atoms (“Mona” refers to “Mono,” meaning something being ONE, remember!). Examples of monatomic elements are the noble gases, such as: Helium, Neon, Argon,Krypton, Radon, etc..

Answer 2

Some atoms - hydrogen, oxygen, nitrogen - like to bond with themselves - hence hydrogen gas isn’t just a bunch of individual atoms floating around - they go around in pairs. Same with oxygen, etc.

However, other atoms don’t react with each other - so (for example) Helium atoms do fly around by themselves - never in pairs.

These second kinds of elements are “monatomic”.

The most obvious ones are the ones on the right of the periodic table: Helium, Neon, Argon, Krypton, Xenon.

However, out in very deep space - there can be so few atoms around that they don’t find others to bond with - so you can find “monatomic hydrogen” out there. But this doesn’t happen in “normal” situations.