Use the following decay curve for iodine-131 to answer problems a to c: (5.4) a. Complete the values for the mass of radioactive iodine-131 on the vertical axis. b. Complete the number of days on the horizontal axis. c. What is the half-life, in days, of iodine-131

a. 80 g ⟶ 40 g ⟶ 20 g ⟶ 10 g ⟶ 5 g …

b. 0 da ⟶ 8 da ⟶ 16 da ⟶ 24 da ⟶ 32 da …

c. 8 da

Explanation:

Assume that the decay curve looks like the first one below.

a. Mass of I

The mass of iodine decreases by half after each half-life.

Thus, the masses decrease in the sequence

80 g ⟶ 40 g ⟶ 20 g ⟶ 10 g ⟶ 5 g …

b. Time

The horizontal axis has repeating units every 8 da.

Thus, the time increases in the sequence

0 da ⟶ 8 da ⟶ 16 da ⟶ 24 da ⟶ 32 da …

The completed graph is the second one below.

c. Half-life

It takes 8 da for 80 g of iodine to decrease to 40 g.

The half-life of iodine is 8 da.

indium, and thallium have three electrons i think

catya your not at all which answer i've seen you do this on another question!