What are the three particles of an atom?
a. proton, ion, and valencium
b. proton, neutron, and electron
c. electron, proton, and isotope
d. neutron, electron, and ion

The three particles of an atom is B; Protons, Neutrons, and electrons.

Here's more facts according to Google.com
"Protons have a relative mass of 1 and a charge of +1, and they are found in the nucleus of an atom. Neutrons have a relative mass of 1 and no charge, and they are also found in the nucleus of an atom. Electrons have a relative mass of 1/1836 and a charge of -1."

I truly hope I helped!

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