The subatomic particles are electrons, protons and neutrons (the two later are in the nucleus of the atom).
Charges: neutron has not charge (it is neutral). Electrons are negatively charged and proton are positively charged. The magnitud of the charges of electrons is equal to the magnitude of the charges of the protons. Then the atoms have the same number of protons than electrons are they are neutral.
Mass: Protons and neutrons have almost the same masses( about 1.67*10^ - 31 kg). Electrons have a mass much, much lower thatn protons. The ratio of the mass of a proton to the mass of an electron is about 1836.
We use the gas law named Charle's law for the calculation of the second temperature. The law states that, V₁T₂ = V₂T₁ Substituting the known values, (0.456 L)(65 + 273.15) = (3.4 L)(T₁) T₁ = 45.33 K