Question

1. if an astatine - 210 atom, element 85, undergoes alpha decay, what atom will be produced? 9. if a francium - 223 atom, element 87, undergoes beta decay, what atom will be produced?

Explanation:

Step1: Recall beta - decay rule

In beta - decay, a neutron in the nucleus is converted into a proton, an electron, and an antineutrino. The atomic number (Z) increases by 1 while the mass number (A) remains the same. For francium - 223 ($_{87}^{223}Fr$), after beta - decay, the atomic number becomes $87 + 1=88$ and the mass number is still 223. The element with atomic number 88 is radium (Ra). So the resulting atom is radium - 223 ($_{88}^{223}Ra$).

Step2: Recall alpha - decay rule

In alpha - decay, an alpha particle ($_{2}^{4}He$) is emitted from the nucleus. The atomic number (Z) decreases by 2 and the mass number (A) decreases by 4. For astatine - 210 ($_{85}^{210}At$), after alpha - decay, the atomic number becomes $85−2 = 83$ and the mass number becomes $210−4=206$. The element with atomic number 83 is bismuth (Bi). So the resulting atom is bismuth - 206 ($_{83}^{206}Bi$).

Answer:

For francium - 223 undergoing beta - decay, the produced atom is radium - 223 ($_{88}^{223}Ra$). For astatine - 210 undergoing alpha - decay, the produced atom is bismuth - 206 ($_{83}^{206}Bi$).