B an egg released from the ovary. It’s probably wrong
Iodine-131 has a half life of 8 days, so half of it is gone every 8 days.
10 grams of iodine-131 is left for 24 days.
At 8 days: 10/2=5 grams left
At 16 days: 5/2=2.5 grams left
At 24 days: 2.5/2=1.25 grams left.
**
Your mistake is that you stopped at 16 days.
Explanation:
Answer is B.
B. It has a central nucleus composed of 29 protons and 35 neutrons,surrounded by an electron cloud containing 29 electrons.
I hope it's helpful!