Plz help dont understand.

Question

Enter a nuclear equation for the alpha decay of each nuclide.

Part A

Po-214

Part B

Po-210

Part C

Th-227

Answer 1

Alpha decay is the emission of a helium nucleus, i.e. ⁴₂He

So, the daughter should have atomic number (protons) 2 less and atomic mass 4 less than parent

So, in general, for alpha decay you can write ^A_ZX ==> ^A-4_Z-2X + ⁴₂He

Po-214 is ³¹⁴₈₄Po and then ²¹⁴₈₄P ==> ²¹⁰₈₂Pb + ⁴₂He

Po-210 is ²¹⁰₈₄ Po and then ²¹⁰₈₄ Po ==> ²⁰⁶₈₂Pb + ⁴₂He

Th-227 is ²²⁷₉₀Th and then ²²⁷₉₀Th ==> ²²³₈₈Ra + ⁴₂He