Question

Which two particles make up most of the mass of a hydrogen-2 atom?

(1) electron and neutron
(2) electron and proton
(3) proton and neutron
(4) proton and positron

Answer 1

Electrons and positrons have a relative mass of 0
Hydrogen-2 (Or deuterium) is made up of a proton, a neutron, and an electron
So the answer is (3) proton and neutron

Answer 2

Answer;

(3) proton and neutron

Step-by-step explanation;

-Protons and neutrons are the two particles of an atom that make up the most mass of an atom. Almost all of the mass in an atom is made up from the protons and neutrons in the nucleus with a very small contribution from the orbiting electrons.

-Neutrons have no charge and protons are positively charged, thus the nucleus is positively charged since it is only made up of protons and neutrons.