The atom with the smallest atomic mass is hydrogen (H).
Details:
- Atomic mass of hydrogen = 1.008 u
- It consists of:
- 1 proton
- 1 electron
- Usually no neutron (in its most common isotope, protium)
Why is it the smallest?
- Hydrogen has the simplest atomic structure
- It is the first element in the periodic table
Key Takeaway:
Hydrogen is the lightest element and has the smallest atomic mass (-1 u) among all atoms.