- #1
Garlic
Gold Member
- 181
- 72
Hello,
A few days ago I tried to calculate the decay heat of Americium in a Smoke Detector, but as I was trying to find the volume it should have, my calculations showed that its volume should be really small (smaller than a cubic micrometer), but it was obvious that it couldn't be so small (I've seen the Americium piece inside a Smoke detector, and there was at least a cubic milimeter of it).
I thought I probably made a mistake in my calculations, so I did it again.
The amount of Americium (not Americium Oxide) in a smoke detector is 0.28 μg, but I am taking it roundly as 0.3μg.
The isotope Americium 241 has a molar mass of roundly 241 g/moles, and we have 3x10^-7 grams of it. So it must be 1.245x10^-9 moles.
The molecule AmO2 (Americium Oxide) mas a molar mass of 275 g/moles and a density of 11.68 g/cm^3.
275 g/moles x 1.245x10^-9 moles = 3.423x10^-7 grams.
(11.68 g/cm^3) / (3.423x10^-7 g) = 3.4122x10^-7 cm^3 = 3.4122x10^-4 mm^3 = 0.34122 μm^3
(Where) did I make a mistake here?
Thank you
A few days ago I tried to calculate the decay heat of Americium in a Smoke Detector, but as I was trying to find the volume it should have, my calculations showed that its volume should be really small (smaller than a cubic micrometer), but it was obvious that it couldn't be so small (I've seen the Americium piece inside a Smoke detector, and there was at least a cubic milimeter of it).
I thought I probably made a mistake in my calculations, so I did it again.
The amount of Americium (not Americium Oxide) in a smoke detector is 0.28 μg, but I am taking it roundly as 0.3μg.
The isotope Americium 241 has a molar mass of roundly 241 g/moles, and we have 3x10^-7 grams of it. So it must be 1.245x10^-9 moles.
The molecule AmO2 (Americium Oxide) mas a molar mass of 275 g/moles and a density of 11.68 g/cm^3.
275 g/moles x 1.245x10^-9 moles = 3.423x10^-7 grams.
(11.68 g/cm^3) / (3.423x10^-7 g) = 3.4122x10^-7 cm^3 = 3.4122x10^-4 mm^3 = 0.34122 μm^3
(Where) did I make a mistake here?
Thank you