Question

The mass of an atom is found by adding its protons and (space) The electric charge of an atom is found by adding the charges carried by its protons and (space)
(First space)
1.electrons
2.neutrons
3.nucleus
(second space)
1.electrons
2.neutrons
3.nucleus

Answer 1

First one  is neutron next one is elcectron

Answer 2

atoms are made of 3 types of subatomic particles; protons, neutrons and electrons

protons and neutrons both have a mass of 1 atomic mass unit each. mass of an electrons is 1/1836 of atomic mass unit which is insignificant compared to mass of protons and neutrons.

protons and neutrons are located in the nucleus.

1) the mass of an atom is found by adding its protons and neutrons.

Protons are positively charged and electrons are negatively charged. Neutrons are neutral. the net charge of an atom is the sum of charges of protons and neutrons.

2) The electric charge of an atom is found by adding the charges carried by its protons and electrons.