Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182,
= 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;

For two half lives, t = 2 × 
∴ t = 2 × 15 = 30


∴ The amount left, N(t) = 0.75 grams
Li is in group 1 so it has same number of valence electrons as hydrogen.
hope it helps.
Answer:
The Flow rate = 0.0208 mL/min
Explanation:
Data provided:
Rate of dose = 39 mg every 30 min = (39/30) mg/min = 1.3 mg/min
also,
125mg of methylprednisolone is present in every 2 mL
thus,
concentration = (125/2) mg/mL = 62.5 mg/mL
Now,
The flow rate is given as:
Flow rate = Rate / Concentration
on substituting the respective values, we get
Flow rate = (1.3 mg/min) / (62.5mg/mL)
or
The Flow rate = 0.0208 mL/min