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tonesack tonesack
wrote...
11 years ago
So say that Neon has a Mass Number of 20 and Atomic Number of 10. Does anyone know how to deduce the number of protons, neutrons and electrons that it possesses?
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obb Author
wrote...
11 years ago
# protons = atomic number
# neutrons = atomic mass - atomic #
# electrons = # protons in a neutral atom

Neon has

# protons = 10
# neutrons = 20-10 = 10
# electrons = 10
wrote...
11 years ago
The atomic number is defined as the number of protons in the atoms core. Neon always has 10 protons in its core, otherwise it wouldn't be neon. Because it has 10 positively charged protons, it also has to have 10 negatively charged electrons.

The mass of an atom is almost entirely determined by the amount of neutrons and protons, both neutrons and protons roughly weigh one u (1/12 of the mass of a Carbon12  atom) so a total mass of 20 means 10 neutrons.
wrote...
11 years ago
since neon has a mass number of 20 that means that:
# of protons + # of neutrons = 20
since neon has an atomic number of 10:
# of protons = 10
and since the # of protons and # of electrons are ALWAYS equal:
# of electrons = 10

The number of electrons are never used in the mass number because they weigh 1 /2000 AMU.  So, since we know that there are 10 protons you must subtract that from the mass number to get the number of neutrons.

Mass # ( 20 ) - # of protons ( 0 ) = # of neutrons (10)
jags Author
wrote...
11 years ago
What about electrons.javascript:void(0)
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