How do you figure out how many protons, neutrons, and electrons there are?

I think you'd need to start by knowing the mass of the universe and
then estimate how many atoms exist in it and then take it from there.

Hi ciao,

I'm not a scientist, but I found your question intriguing. With my
limited science knowledge, this is what I found:

" How many atoms there are in the entire Universe. <...>
It is a very large number, but it is finite, and is 10 followed by 80
zeros, (maybe a few more zeros, maybe a few less), expressed as 10 to
the 80th. If you want to see what it looks like.........

100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.

0r written as - One hundred million, billion, billion, billion,
billion, billion, billion. billion, billion."

http://www.thekeyboard.org.uk/What%20is%20infinity.htm

This site offers a formula for calculating the number obtained above:

http://www.sunspot.noao.edu/sunspot/pr/answerbook/universe.html#q70

Now, you are after all the protons, neutrons and electrons. I guess
you will need to determine the elements that make up the Universe and
in what proportions, then calculate the atomic number for each of
these elements, then crunch those numbers together.

The Structure of Atoms
http://encarta.msn.com/text_762504460__1/Chemistry.html

I think you'll need a good formula and a good calculator! Or a good
samaritan scientist to help you.

Good luck.

* j *

Is the questions related the any given element ... like Na (sodium), K
(potassium), H (hydrogen ) etc ??

Sorry ciao,

In retrospect, I think I misunderstood. If your query is about basic
chemistry, please post a comment to clarify. A Google Answers
researcher or canny commenter can probably assist.

* j *

I think there are far more simple atoms in the uiverse than compex
ones. I think Hydrogen is the most common element and the heavier
atoms are much more rare.

I think that the more complex atoms are only be created by 2nd
generation and later stars.

The number of electrons is equal to the number of protons. The protons
+ neutrons equals the mass number. So if you know what the mass number
is than subtract the number of protons to find the number of neutrons
or the number of neutrons to find the protons. Or to find the protons
you can also check the atomic number. Of course, don't forgot the
number of protons is equal to electrons. I'll organize it.

Electrons: To find this look at the number of protons. If you don't
know what the number of protons is, look at the atomic number, because
protons are the same as the atomic number, and electrons are the same
as protons. This is assuming it is not an isotope, which are unstable,
unbalanced atoms without an equal number of electrons and protons.

Protons: The number of protons is equal to the atomic number. It is
also equal to the number of electrons, assuming the atom is not an
isotope. You can also find protons by taking the mass number and
subtracting the number of neutrons in the atom from it, because
neutrons + protons = mass number.

Neutrons: Number of protons subtracted from mass number.

http://education.jlab.org/qa/pen_number.html

try,  www.howstuffworks.com