Question

An element X with atomic number 90 and mass number 232 loses one α- and two β-particles successively to give a stable species Z. What would be the atomic number and atomic weight of Z

• A. $90Z^{228}$
• B. $91Z^{235}$
• C. $90Z^{235}$
• D. $91Z^{238}$

Answer 1

Answer: (A)

$90Z^{228}$

Answer 2

At. no. and At. wt. of the element (Y) produced by the loss of One α-particle $(_{2}He^{4})$ from $90X^{232} =_{88}Y^{228}$

At. no. and At.wt. of Z produced by the loss of 2 β-particles $(_{- 1}e^{0})$ from $Y =_{90}Z^{228}$