Occurrence Of Noble Gases

Question 1

What all gases occur in atmosphere?

Answer 1

All gases except Radon(Ra) and Oganesson(Og) occur in the atmosphere

Question 2

What is the abundance of noble gases in the atmosphere?
What is the main constituent of dry air?

Answer 2

Abundance (approx) - 1%
Main constituent of dry air - Argon

Question 3

Which gases are SOMETIMES found in radioactive origin?
OR
Which other noble gases are radioactive other than Radon and Oganesson?

Answer 3

He and Ne are sometimes radioactive in origin
Example- Pitchblende
Cleveite
Monazite

Question 4

What is the commercial source of He?

Answer 4

Natural Gas

Question 5

What are the rarest element of the group?

Answer 5

Xenon(Xe) and Radon(Rn)

Question 6

How is Radon obtained? Which is the other noble gases obtained along with Rn?

Answer 6

Obtained as Radioactive decay product of Ra²²⁶
The other noble gas obtained - Helium

Question 7

How is Og produced?

Answer 7

Synthetically produced by collision of 98Cf²⁴⁹ (Californium) atoms and 20Ca⁴⁸ (Calcium) ions

Question 8

Isotope of which noble gas is Isotonic (Same number of neutrons) with Tritium?

Answer 8

Helium is isotonic with Tritium

Question 9

Which noble gas is discovered in the chromosphere of Sun?

Answer 9

Helium

Question 10

The ratio of Cp/cv for noble gases is

Answer 10

The ratio of Cp/cv for noble gases is 1.67

Question 11

What is the order of heats of vaporization of noble gases?

Answer 11

Order of heats of vaporization of noble gases
He<Ne<Ar<Kr<Xe<Rn

Question 12

When a radioactive substance is kept in a vessel the atmosphere around it is rich with which noble gas?

Answer 12

Helium

Question 13

Noble gases are also known as Aerogens. Why?

Answer 13

Noble gases are also known as Aerogens
Reason- Since most of them are available in air

Question 14

Helium is believed to be the decay product of which radioactive elements?

Answer 14

Helium is believed to be decay product of radioactive metals like Thorium ,Uranium and radium