helium
Yes, it is.
Oh, dude, you're asking about argon? That's like the introvert of the periodic table. Yeah, it's lighter than air because it's a noble gas, so it just chills at the top of the party, not getting involved in any drama. So, yeah, if air was a high school cafeteria, argon would be that cool kid sitting at the cool kids' table, just floating above it all.
A balloon filled with argon will sink because argon is denser than air. The density of a gas affects its buoyancy in the surrounding air; denser gases will sink while lighter gases will rise.
Argon being heavier than air is important because it allows it to displace and push away lighter gases, preventing them from mixing with the argon. This property makes argon useful for applications like shielding gases in welding and as a protective atmosphere in certain industrial processes.
Chlorine diffuses faster than argon because it is a lighter and smaller molecule. This allows chlorine to move more quickly through a medium compared to argon, which is a heavier and larger molecule.
Argon is 1.4 times heavier than air.
argon is a component of "air" and as such air cannot be lighter than air, only more or less dense, however, judging from atomic masses, yes argon is heavier than nitrogen, oxygen, helium, and hydrogen, but depending on pollutants and other gases (CFC's, HCFC's, etc.) the compound that is air can vary slightly in mass.
When helium and argon are mixed together, they form a homogeneous mixture known as a gas blend. The properties of the gas blend will depend on the ratio of helium to argon in the mixture. Helium is lighter than argon and less soluble in liquids, so it tends to rise to the top of the mixture when not in a pressurized container.
atoms of argon are heavier than atoms of nitrogen
No. The molar mass of dry air is 28.97 g/mol. Noble gases are monatomic, so their atomic mass represent their molar mass. From this we can tell that helium and neon are less dense (lighter) than air, while argon (atomic mass 39.9) onwards are denser than air.
"Gas" could mean anything - there are many different types of gases. Some are lighter than air (composite of mostly nitrogen and oxygen) like methane or helium and some are heavier like argon or carbon dioxide.
Yes, xenon is larger than argon. Xenon has more electrons and a larger atomic radius compared to argon.