Question

Protactinium-231 undergoes alpha decay as shown:

231 Pa → 4X + He
Enter the appropriate values for A and Z and the chemical symbol for X.

A. A: 227, Z: 88, X: Ra
B. A: 227, Z: 89, X: Ac
C. A: 230, Z: 88, X: Ra
D. A: 230, Z: 89, X: Ac

Answer 1

In alpha decay, the mass number decreases by 4 and the atomic number decreases by 2. The correct values for A, Z, and the chemical symbol for X in the given alpha decay equation are A: 227, Z: 88, X: Ra.

Step-by-step explanation:

The given alpha decay equation is:

231 Pa → 4X + He

In alpha decay, the mass number (A) decreases by 4 and the atomic number (Z) decreases by 2. The resulting nuclide is X. Based on this information, we can determine the values for A, Z, and the chemical symbol for X.

From the answer choices, the correct values are:

A: 227, Z: 88, X: Ra

Therefore, option A is the correct answer.