The noble gases are present to the extent of about 1% in the earth's atmosphere, the chief component being argon
B
Helium is the second most abundant element in the universe after hydrogen
C
There are two stable isotopes of helium 23He,24He
D
24He ise formed by thermonuclear fusion reaction in stars 411H⟶24He+21e0
Medium
Open in App
Solution
Verified by Toppr
Correct options are A) , B) , C) and D)
The relative abundance in dry air by volume (ppm) of different noble gases is
He5.24Ne18.18Ar93.40Kr1.14Xe0.09Rntraces
Mass decrease (amu)
Energy released(KJmol−1)
12H+12H→24He
0.026
2.3×109
12H+13H+4He2+1n0
0.018
1.79×109
4H11→He24+2e−10
0.029
2.6×109
Hydrogen is the most abundant element in the known Universe; helium is second.This was earlier rank process which was not followed after this as rank of oxygen is 3 but atomic no. of oxygen is 8.
Although there are nine known isotopes of helium (He) but only helium-3 (3He) and helium-4 (4He) are stable.