What is the total mass of <span title="protons&electrons&neutrons">protons&electrons&neutron...</span> that make up an atom?

Question

What is the total mass of protons&electrons&neutron... that make up an atom?

Answer 1

It depends on the element look it up in the periodic table.

Answer 2

Hi

I don&#039;t fully understand the question but the mass of protons, electrons and neutrons are equal in an Atom, the structure of an Atom is a diameter of 10-8 centimetre&#039;s. I hope this helps, when I did Physics Gods dog were a pup.

Ray. West York&#039;s. U.K.

Answer 3

The total mass of an atom is not equal to the sum of its protons, neutrons and electrons because of the binding mass/energy.

Answer 4

Quite simply you have your nucleus (middle of the atom) which consists of protons and neutrons and then you have your electrons which orbit the nucleus and are equal to the number of protons in the nucleus. It is the neutrons which provide the mass of the atom, known as the atomic mass and is calculated by nucleons (protons+neutrons) minus protons.

Answer 5

Your Question is not clear.

Answer 6

what atom are you talking about

Answer 7

Well, protons and neutrons have the same weight (almost), which is 1.67x10^-27 Kg for just one of them, and that would look like:

0.000 000 000 000 000 000 000 000 001 67 Kilograms,

While an electron is even lighter; 1/1836 of this mass, which is 9.11x10^-31 Kg, which would be:

0.000 000 000 000 000 000 000 000 000 000 911 Kilograms

Obviously an atom usually has a number of each of these, and though the weights are difficult to imagine you can see just how incredibly light they are.

Answer 8

the mass is usually the protons and neutrons, called &quot;Atomic Mass&quot;

Answer 9

The mass of an atom may be considered in terms of the electrons mass sum and the nucleus mass. The electron mass is simply Z.m(electron), where &#039;Z&#039; is the nuclear charge and &#039;m(electron)&#039; is the mass of an electron. The mass of the nucleus may be calculated as follows: -

The mass of the nucleus is less than the sum of the nucleons because mass-energy has been lost to the binding energy.

The liquid drop model of the nucleus (Bohr 1936) gives the mass of the nucleus &#039;M&#039; as: -

M = Z.M(protons) +(A - Z).M(neutrons) - BE/c²

Where &#039;Z&#039; is the proton number and &#039;A&#039; the atomic number with &#039;BE&#039; as the binding energy given by: -

BE = av.A - 4.ac.(Z.(Z-1)/A^(1/3)) - as.A^(2/3) -ar.((A - 2.z)²/A) + E

Where the coefficients have values: -

av = 14.0 Mev, ac =0.146 Mev

ar = 19.4 Mev, as = 13.1 Mev

E varies as follows: -

A..........Z..........N..........E

even....even....even....+δ/2A

odd.....even....odd......0

odd.....odd......even....0

odd.....odd......odd.....-δ/2A

And

δ = 270 Mev.

This mass equation is known as the &#039;semi-empirical mass formula&#039; and was derived by considering the nucleus as a liquid drop, with volume energy (the av term), Coulomb energy (the ac term), surface energy (the as term), a symmetry effect due to the neutron excess (the ar term). It works with medium and heavy nuclei (large numbers of nucleons) but does not work well with small or light nuclei (few nucleons).

Hence, to good approximation for medium to heavy atoms - the mass of the atom is: -

M = Z.m(electron) + Z.M(protons) +(A - Z).M(neutrons) - BE/c²