Sodium-25 after 3 minutes : 1.0625 mg
<h3>Further explanation</h3>
General formulas used in decay:

T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
<h3 />
No=8 mg
t1/2=60 s
T=3 min=180 s

C I’m pretty sure. I can explain just lmk
Hello there!
The statement that Acid strength in a series of H-A molecules increases with increasing size of A is True.
When only the size is involved, increasing the size will increase the Acid strength because as size increases, the H-A bond will become weaker as the atoms will be farther apart. Acid strength is related to the ability to release H⁺ ions and a weaker H-A bond will release H⁺ more easily.
Have a nice day!