<span>The correct answer is the first option. Electron is not found in the nucleus of an atom. The sub-atomic particles of an atom are the
proton, electron and the neutron. An electron has a charge of -1 and a
smaller mass than a proton. Proton has the same mass with the neutron. The
ratio between the mass of a proton and an electron is about 2000. An electron
has an equal value but negative charge with the proton.</span>
Answer:
D
Explanation:
B is solid and liquid while D is liquid and gas
Simple. The atomic number is the number of protons (12) and the mass number is the number of neutrons and protons combined. So you'd subtract 12 from 25 (25-12=) and that'd get you 13 as your answer. If you need to find the number of electrons, it'll be the same as the number of protons unless it has a certain charge and if it does, if it's positive it has more protons (+) than electrons (-), if it is negative it has more electrons (- negatively charged) than protons (+ positively charged)
