Question

29 select the correct answer. use the periodic table to determine what element cesium - 135 ($_{55}^{135}$cs) becomes after beta decay. a. $_{55}^{135}$cs b. $_{53}^{131}$i c. $_{57}^{139}$la d. $_{56}^{135}$ba

Explanation:

Step1: Recall beta - decay concept

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

Step2: Identify cesium's atomic number

Cesium ($Cs$) has an atomic number of 55. After beta - decay, the atomic number will be $55 + 1=56$.

Step3: Find the element with atomic number 56

Looking at the periodic table, the element with atomic number 56 is barium ($Ba$). The mass number of the resulting barium isotope is the same as the initial cesium isotope (135 in this case).

Answer:

D. $^{135}_{56}Ba$