Answer:
The new element will be thorium-226 (²²⁶Th).
Explanation:
The beta decay is given by:
[tex] ^{A}_{Z}X \rightarrow ^{A}_{Z+1}Y + \beta^{-} + \bar{\nu_{e}} [/tex]
Where:
A: is the mass number
Z: is the number of protons
β⁻: is a beta particle = electron
[tex]\bar{\nu_{e}}[/tex]: is an antineutrino
The neutral atom has 88 electrons, so:
[tex] e^{-} = 88 = Z [/tex]
Hence the element is radium (Ra), it has A = 226.
If Ra undergoes 2 rounds of beta minus decay, we have:
[tex] ^{226}_{88}Ra \rightarrow ^{226}_{89}Ac + \beta^{-} + \bar{\nu_{e}} [/tex]
[tex] ^{226}_{89}Ac \rightarrow ^{226}_{90}Th + \beta^{-} + \bar{\nu_{e}} [/tex]
Therefore, if a neutral atom with 88 electrons undergoes 2 rounds of beta minus decay the new element will be thorium-226 (²²⁶Th).
I hope it helps you!
