Which contributes more to an atom's mass: electron orprotons? Which contributes more to an atom's size? -------------------------------------- A proton is about 2000 times as massive as an electron. I am thinking that electrons contribute more to their size but Imnot sure why because they are so small. Which contributes more to an atom's mass: electron orprotons? Which contributes more to an atom's size? -------------------------------------- A proton is about 2000 times as massive as an electron. I am thinking that electrons contribute more to their size but Imnot sure why because they are so small.
Explanation / Answer
Protons contributes more to an atom's mass electrons contribute more to an atom's size because electrons revolves around the nucleus in orbits.Theseorbits are spacious when compared to size of the nucleus.