[brainly] 10 fish boiiiiiiiiiiiiiiiiiiiiii
A. the existence of other galaxies
I did some quick research, and your answer would be the Organisation for Economic Co-operation and Development. Hope this helps!<span>
</span>
The correct answer is- Proton
A proton is approximately 2,000 times heavier than an electron. In most cases, atoms have an equal number of protons and electrons. However, because protons are so much heavier than electrons, the electrons do not make a significant contribution to the mass of an atom.