Question

an Alpha particle changes into a Helium atom in the course of one year the volume of helium collected from a sample of Radiant was found to be 1.12 into 10 power minus 2 ML at STP the number of Alpha particles emitted by the sample of Radium in the same time is

Answer 1

Answer:

The number of Alpha particles emitted by the sample of Radium is $3.0076\times 10^{17}$.

Explanation:

Volume of the helium gas = V = $1.12\times 10^{-2} mL=1.12\times 10^{-5} mL$

Pressure of the helium gas = P = 1 atm [STP]

Temperature of the gas = T = 273.15 K

Moles of helium gas = n

$PV=nRT$

$1 atm\times 1.12\times 10^{-5} L=n\times 0.0821 atm L/mol K\times 273.15 K$

$n=\frac{1 atm\times 1.12\times 10^{-5} L}{0.0821 atm L/mol K\times 273.15 K}$

$n=4.99\times 10^{-7} mol$

Alpha particle changes into a Helium atom, So moles of helium obtained were the moles alpha particles produced by radium.

Moles of helium = Moles of alpha particle = $4.99\times 10^{-7} mol$

1 mol = $6.022\tims 10^{23}$ atoms/ ions=/ molecules/ particles

Number of alpha particles:

$4.99\times 10^{-7} mol\times 6.022\tims 10^{23}=3.0076\times 10^{17}$

The number of Alpha particles emitted by the sample of Radium is $3.0076\times 10^{17}$.

Answer 2

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