Question

Which answer choice represents a balanced alpha emission nuclear equation? A. 52 26 Fe --> 52 25 Mn+ 0 ⁺1 e. B. 235 92 U --▻ 239 94 Pu + 4 2 He C. 189 83 Bi --▻ 185 81 Tl + 4 2 He D. 14 6 C --▻ 14 7 N + 0 -1 e

Answer 1

alpha emission is the loss of a helium particle, it removes 2 neutrons and 2 protons from the original atom. the answer is C. 

Answer 2

Answer is "C".

alpha decay is an emission of ₂⁴He nucleus. If an element undergoes an alpha decay, the mass of the daughter nucleus formed is reduced by 4 compared to mass of parent atom while the atomic number of parent atom is reduced by 2.

Here, Bi has atomic number as 83 and mass number as 189. When undergoing an alpha emission, formed daughter atom will has 83 - 2 = 81 as atomic number and 189 - 4 = 185 as mass number. The element which has 81 as its atomic number is Thallium (Tl).