Question

Why can't Alpha particles be 4 times charged hydrogen atoms?
​​​​​ why are they double charged Helium atoms

Answer 1

Since the alpha particle is nothing but positively charged helium nuclei, it has charge of two time of that of the proton, as it is constituted of 2 protons.The rest mass of the alpha particle amounts to 6.64424·10-27 kg, or 3.7273·109 eV, which is almost 4 times of that of proton. You can think it easily considering a positively charged helium nuclei. Now it is obvious that the positively charged He nuclei has 2 protons and 2 neutrons. Now it is known that the mass of proton is e(approx. 1.67×10^-27 kg). Since helium nuclei is consisted of 2 protons and 2 neutrons the mass of it is 6.64×10^-27 kg. Besides we also know that the charge of proton is approx. 1.602×10^-19 C. Hence multiply it by 2 and you will get your answer approx. 3.34×10^-27 C