Answer:
a. 1
Explanation:
Radon is a member of group 18. It is an odorless heavy gas, that emanates from materials that contain uranium.
Rn is a decay product of 226-Ra, a member of the uranium decay series. The spontaneous decay of Rn decay leads to the emission of an alpha particle.
Rn has a half-life of about 3.8 days and its decay product is 218Po.
The nuclear reaction which shows a spontaneous decay is Rn 21% Po + He.
What is spontaneous reaction?
Those reaction in which value of their enthalpy change and change in Gibb's free energy is negative, are spontaneous in nature.
Among all of the given reaction, only first reaction is spontaneous in nature because the given element Radon (Rn) is the product of the decay of uranium series. And in this reaction energy is emitted in the form of alpha particles.
Hence, option (1) is correct.
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what chemical reaction type is Pb + 2 H3PO4 --> 3 H2 + Pb3(PO4)2
Answer:
single displacement reaction
Explanation:
it is because an atom(Pb) dispalces another atom(H) in H3PI4
The given chemical reaction is single displacement reaction.
What is single displacement reaction?When one element in a molecule gets replaced by another, is therefore called a single displacement reaction.
The given reaction is Pb + 2 H3PO4 → 3 H2 + Pb3(PO4)2
It can be seen that when lead is treated with H3PO4 then it will give Pb3(PO4)2 and hydrogen reaction. It is a kind of single displacement reaction.
Therefore, the given reaction is single displacement reaction.
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