A 300 g sample of thorium -234 has a half-life of 24 days. The mass of thorium, in grams, that remains after t days can be modelled by M(t)=300((1)/(2))^(t)/(24) What mass will remain after 31 days? a) 122.5 g b) 193.75 g c) 1508 d) 177 .5g

## Step 1: Calculate the exponent### The time elapsed is 31 days, and the half-life is 24 days. The exponent in the formula is , so we calculate .## Step 2: Calculate the remaining mass### Substitute into the given formula: .