Historically the dining room is furnished with a rather large dining table and a number of dining chairs; the most common shape is generally rectangular with two armed end chairs and an even number of un-armed side chairs along the long sides.
Protons and neutrons do not have the same mass. Their masses are quite close, but they are noticeably different. For some purposes it is okay to equate the neutron and proton mass, but it's just an approximation.Also, neutrons decay into a proton, an electron and an antineutrino.rotons and neutrons do not have the same mass. Their masses are quite close, but they are noticeably different. For some purposes it is okay to equate the neutron and proton mass, but it's just an approximation.
In The Nucleus. The nucleus of an atom is made up of protons and neutrons; protons have a positive electric charge whereas neutrons have none. Protons and neutrons have similar mass, with each having about 2,000 times the mass of an electron.