1) what is the daughter nucleus when ^227Th undergoes alpha decay?

Question

2) what is the daughter nucleus produced when ^227Ac undergoes beta decay by emitting an electron? 

Answer 1

(1)

 

The atomic number of Th is 90.  In alpha decay, It loses 2 protons and 2 neutrons.

 

Z = 90 - 2 = 88, which is the atomic number of Ra

 

A = 227 - 4 = 223

 

Final product:  ₈₈Ra²²³

 

(2)

 

The atomic number of Ac is 89.  In beta decay it gains a proton, with no change in mass number.

 

Z = 89 + 1 = 90, which is the atomic number of Th.

 

A = 227 (no change)

 

Final product:  ₉₀Th²²⁷