What is the value of x in the nuclear reaction above?
Answer Details
The given nuclear reaction represents the radioactive decay of 226Ra into an unknown nucleus (represented by the symbol 'x') and an alpha particle (α).
An alpha particle is a positively charged particle that is identical to the nucleus of a helium atom. It consists of two protons and two neutrons.
During the radioactive decay process, the nucleus of 226Ra loses an alpha particle, which means it loses two protons and two neutrons. This results in the formation of a new nucleus with a different atomic number and mass number. The atomic number of an element is equal to the number of protons in its nucleus. Therefore, the atomic number of the unknown nucleus 'x' can be calculated by subtracting the number of protons lost (i.e., two) from the atomic number of 226Ra, which is 88.
88 - 2 = 86
Hence, the atomic number of the unknown nucleus 'x' is 86. This corresponds to the element radon (Rn). Therefore, the value of x in the given nuclear reaction is 222, which is the atomic mass number of radon.
So, the correct answer is (B) 222.