Regents Chemistry Exam January 2023
2 Which two particles each have a mass approximately equal to one atomic mass unit? (1) positron and proton
(2) positron and electron
(3) neutron and electron
(4) neutron and proton
Solution: Proton and neutron have a mass approximately equal to one atomic mass unit. Electron is very light and positron has the same weight as an electron but opposite charge.
Answer: 4