210 total combined
As for all other elements: neutrons, protons and electrons.
Protons/Electrons: 85 Number of Neutrons: 125
Astatine, a radioactive element found in the halogen group, has at least 20 known isotopes. However, only one of these isotopes, Astatine-210, is considered stable. The other isotopes are unstable and undergo radioactive decay.
Astatine has 85 protons.
Each isotope has a different number of neutrons. Number of neutrons = Atomic mass of the astatine isotope - 85
Astatine has 125 neutrons
210 total combined
As for all other elements: neutrons, protons and electrons.
Astatine has many isotopes, each with its own half life. The longest in my list is At209 at 8.1 hours, and At215 is listed at 0.1 ms. The shortest are just listed as 'short' reflecting the small quantities.
Number of neutrons = Mass number - atomic number = 210 - 82 = 128
Polonium-210 has 84 protons, 84 electrons and 126 neutrons.
The atomic mass of astatine is 209.9871 atomic mass units (amu). The atomic mass is given for the longest lived isotope of astatine, which is astatine-210, with a half life of 8.3 hours.
Protons/Electrons: 85 Number of Neutrons: 125
Polonium-210 has 126 neutrons.
Lead-210 has 82 protons, so 128 - 82 = 46 neutrons in Pb-210. Lead-206 has 82 protons, so since it's a different isotope, the number of neutrons will differ. Lead-206 has 206 - 82 = 124 neutrons.
The isotope 210Rn has 86 protons and electrons; also 124 neutrons.