What is the mass of a proton?
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College Student asked:
Is it 0.0005 unit or 1 unit?
Is it 0.0005 unit or 1 unit?
The alpha particles usually passed undeflected but sometimes bounced back when they were aimed at atoms indicated tha tmost of the atoms mass is located where?
How many neutrons are there in an atom of molybdenum 90 atom? The element is Mo.
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November 8th, 2008 at 3:52 am
Mass of proton : 1.67262 x 10^(-27) kg
November 8th, 2008 at 10:19 am
1 atomic mass unit (it’s really 1.06 something but thats ignored until you get into more advanced stuff, protons and nuetrons are close enough for that to be ignored)
Molybdenum is #42, showing that it has 42 protons. In molybdenum-90, 90 is the mass (mass of electrons are ignored). So 90-42 = 48 nuetrons.
November 9th, 2008 at 11:55 am
A proton weighs 1.0073 amu.
The second statement describes Rutherford’s explanation of the alpha scatter experiment (”gold foil experiment”) conducted by Hans Geiger and Ernest Marsden. Rutherford figured that since most of the alpha particles traveled straight through the gold and were undeflected, that gold was mostly empty space, and that almost the entire mass of the gold atom was found in the nucleus
The alpha particles, with their positive electrical charge, were repelled by the positive charge on the nuclei of atoms.
For your last statement, an atom of Mo-90 contains 42 protons. Subtract 42 from 90, to get the number neutrons in the nucleus. There are 48 neutrons in an atom of Mo-90