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

There you go try that out.
Answer : The mass of solute in solution is
.
Solution : Given,
Molarity = 0.730 M
Volume of solution = 1.421 L
Molar mass of sodium carbonate = 105.98 g/mole
Formula used for Molarity :

where,
w = mass of solute
M = Molar mass of solute
V = volume of solution in liter
Sodium carbonate is solute and water is solvent.
Now put the given values in above formula, we get the mass of solute in solution.

By rearranging the terms, we get

Therefore, the mass of solute in solution is
.
FALSE
Organisms may play only one role in an ecosystem. ... Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.
~~~~iln~~~~~~
Answer:
35.9 ml
Explanation:
Start with the balanced equation:
3CuCl2(aq)+2Na3PO4(aq)→Cu3(PO4)2(s)+6NaCl(aq)
This tells us that 3 moles of CuCI2 react with 2 moles Na3PO4-
∴ 1 mole CuCl2 will react with 2/3 moles Na3PO4
We know that concentration = moles/volume i.e:
c= n/v
∴n=c×v
∴nCuCl2=0.107×91.01000=9.737×10−3
I divided by 1000 to convert ml to L
∴nNa3PO4=9.737×10−3×23=6.491×10−3
v=nc=6.491×10−30.181=35.86×10−3L
∴v=35.86ml