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Which one of the following noble gases is not found in the atmosphere? |
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(a) |
Argon |
(b) |
Krypton |
|
(c) |
Radon |
(d) |
Xenon |
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Which one of the following noble gases is not found in the atmosphere? |
|||
|
(a) |
Argon |
(b) |
Krypton |
|
(c) |
Radon |
(d) |
Xenon |