Question

1. circle the letter of the expression that accurately compares the masses of neutrons and protons.

a. mass of 1 neutron = mass of 1 proton
b. mass of 2000 neutrons = mass of 1 proton
c. mass of 1 electron = mass of 1 proton
d. mass of 1 neutron = mass of 1 electron

Explanation:

• Protons and neutrons are both nucleons. The mass of a proton is approximately \(1.6726\times10^{-27}\space kg\), and the mass of a neutron is approximately \(1.6749\times10^{-27}\space kg\). These values are very close, so we can say that the mass of 1 neutron is approximately equal to the mass of 1 proton.
• Option b is incorrect because a neutron is more massive than a proton, so it would take fewer neutrons to equal the mass of a proton, not 2000.
• Option c is incorrect because an electron has a much smaller mass (\(9.1094\times 10^{-31}\space kg\)) compared to a proton.
• Option d is incorrect for the same reason as option c; a neutron is much more massive than an electron.

Answer:

a. mass of 1 neutron = mass of 1 proton