Which particle does NOT contribute significantly to the atomic mass of an atom?
Electron
The mass of an atom comes from its three kinds of particles. A proton and a neutron each have a mass of about 1 u, while an electron has a mass of only about \(\frac{1}{1836}\) of the mass of a proton.
Because the electron is so light, all the electrons of an atom together add almost nothing to its mass. Nearly the whole mass is concentrated in the nucleus, which is why the mass number is simply the number of protons plus neutrons. So the electron does not contribute significantly to the atomic mass.
Protons and neutrons are the particles that make up almost all of the atomic mass, so they do contribute significantly. The three particles do not contribute equally, because the electron is roughly 1836 times lighter than a proton or a neutron.
Hence, Electron.
Similar Questions
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Statement I: The atom is a sphere of positive charge with electrons scattered inside it.
Statement II: Thomson's model could explain the presence of the nucleus in an atom.
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Which of the following electron transition in hydrogen atom will require largest amount of energy?
A species having 8 electrons in the third shell is very reactive while the other species having 8 electrons in the third shell is very inactive they are :
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