Which particles determine the mass of an atom?

Answer 1

The Atomic Mass unit is defined to be 1/12 of the mass of a carbon-12 atom. Atomic masses can determined by weighing molar amount of an isotope.

Absolute masses (in kg) are determined by measuring the amount that charged atoms are deflected by magnets, since if you know the charge you can calculate mass from the amount of deflection.

Answer 2

Protons and neutrons are the particles that determine the mass of an atom. Electrons have a much smaller mass compared to protons and neutrons, and they contribute very little to the overall mass of an atom.

Answer 3

Only protons and neutrons contribute towards the mass of the atom.

Since mass of protons and neutrons are almost same whereas the mass of an electron is about 1/1800 times the mass of proton. Therefore, mass of electron is not counted towards the mass of the atom since it is almost negligible even in comparison to the

the mass of a proton whose mass itself is very small.

Answer 4

Electrons, more specifically, valence electrons.

Answer 5

Protons and neutrons and in a less proportion electrons.

Answer 6

Atomic mass is determined by the combined masses of the protons, neutrons, and electrons found in an atom.

Answer 7

Atom mass is mainly determined by the number of protons AND neutrons.

Answer 8

All the particles contribute to the mass of the atom; but the contribution of protons and neutrons is important - the contribution of electrons is very low.

Answer 9

Neutrons and protons Atomic mass = mass of protons + mass of neutrons

Answer 10

Protons and neutrons determine the atomic mass of an atom.