Question

Which produces barium-137 when it undergoes gamma decay? A. Cesium-137 B. Cesium-138 C. Barium-137 D. Barium-138

Answer 1

c

Step-by-step explanation:

Answer 2

C. Barium-137

Step-by-step explanation:

We have barium-137

• Required to identify the radioisotope that undergoes gamma decay to produce Ba-137.

We need to know that when a radioisotope undergoes gamma decay its mass number and the atomic number remains unchanged.

• The atomic number of Ba-137 is 56 while the mass number is 137.
• We need to identify the choice whose atomic number is 56 and mass number is 137.

In this case,

• Cesium-137 has a mass number 137 and atomic number 55
• Cesium-138 has a mass number 138 and atomic number 55
• Barium-137, has a mass number, 137 and atomic number 56.
• Barium-138 has a mass number 138 and atomic number 56

Therefore the correct choice is C. Barium-137