# Calculate the difference between the initial and final masses of the reaction

#### subarua

Polonium-212 decays into lead-208 emitting an alpha particle. The mass of polonium is 3.51986x10^-25kg the mass of lead is 3.45323x10^-25kg and the mass of an alpha particle is 6.646x10^-27kg

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#### Woody

Where do these numbers come from?
3x10^25kg is rather a large mass (3,000,000,000,000,000,000,000 metric tonnes)
I guess you might mean 3x10^-25?

You will note that 351.986 - 345.323 = 6.663 not 6.646
so where is the extra 0.017?

I would look to E=mc^2 for the answer.

• 1 person

#### subarua

Where do these numbers come from?
3x10^25kg is rather a large mass (3,000,000,000,000,000,000,000 metric tonnes)
I guess you might mean 3x10^-25?

You will note that 351.986 - 345.323 = 6.663 not 6.646
so where is the extra 0.017?

I would look to E=mc^2 for the answer.
yes, you're correct for -25 I've edited the question thanks!

They gave me that number of 6.646

and for E=mc2 what values am I plugging in where? E(energy=massxspeed of light do I have to add the masses up?

I want to know the difference between the initial mass and the final mass

thanks for you time!

#### oz93666

...and for E=mc2 what values am I plugging in where? E(energy=massxspeed of light do I have to add the masses up?
!!!..Some people just do not click with physics .... It's a great error of the education system to force them to study it ...

Subarus should find something he is interested in and forget physics.

#### neila9876

mass vs energy

Oz:
Maybe some guy might touch something special of the elephant and emit a big "?". It's normal. We should try to find out what Subarua is saying...I feel that he is trying to represent the reaction with only one thing: mass...

#### Woody

What is the Kinetic Energy of the Alpha Particle?
(1/2mV^2) where m is the mass of the alpha particle
How does this relate to the mass deficit?
(i.e. what V in the kinetic energy equation relates to the mass deficit in E=Δmc^2 (where Δm is the mass deficit)

Note that it is the high speed of Alpha Particles that makes this radiation dangerous.
Low speed Alpha particles would just bounce of cell membranes and do no damage.

#### neila9876

Woody:
Your question about the kinematic energy (or say the actual mass) of the alpha particle is worth asking. Is it the accurate experimental data from his lab?

#### Woody

The original post has the feel of a homework problem,
I don't know if the quoted values are correct.
However, the numbers in these problems are usually sensibly representative of the experimentally derived values.