Question

fill in all of the missing information; 2 symbols and 2 numbers (from the letter choices below)
234 a 0
th → b + c
90 91 d
a = 1
b = 2
c = 3
d = 4
a. 0 b. 1 c. -1 d. 2 e. 3 f. 4 g. beta
h. gamma i. alpha j. fr k. ba l. ac m. cs
n. pa o. 87 p. 88 q. 230 r. 232 s. 234
t. 236 u. 238 v. 240 w. proton

Explanation:

Step1: Identify the nuclear - decay type

This is a beta - decay process. In beta - decay, a neutron in the nucleus is converted into a proton, an electron (beta particle), and an antineutrino. The atomic number (number of protons) increases by 1, and the mass number (sum of protons and neutrons) remains the same.

Step2: Determine the daughter nucleus

Thorium (Th) has an atomic number of 90. After beta - decay, the atomic number increases by 1 to 91. The element with atomic number 91 is Protactinium (Pa). So B = N. Pa.

Step3: Identify the emitted particle

In beta - decay, the emitted particle is a beta particle. So C = G. beta.

Step4: Calculate the mass number of the daughter nucleus

Since it is beta - decay and the mass number of the parent nucleus (Thorium - 234) is 234, the mass number of the daughter nucleus and the emitted particle (beta particle has a mass number of 0) also satisfies the conservation of mass number. So D = A. 0. And for the mass number of the parent nucleus and daughter nucleus relationship in this decay, the mass number of the daughter nucleus is 234, and the mass number of the beta particle is 0. The value of A (mass number of the beta particle in this context) is 0.

Answer:

1. A. 0
2. N. Pa
3. G. beta
4. A. 0