Are lead atoms heavier than heliam atoms?

Yes, lead atoms are heavier than helium atoms. Lead has an atomic number of 82 and a much larger Atomic Mass due to its greater number of protons and neutrons, while helium has an atomic number of 2 and a significantly smaller atomic mass. Specifically, the atomic mass of lead is about 207 atomic mass units (amu), compared to about 4 amu for helium. Thus, lead is substantially heavier than helium.