Depends on your definition of smaller, but apparently it's not clear-cut: https://www.quora.com/Which-element-is-bigger-an-atom-of-hydrogen-or-of-helium https:/

Depends on your definition of smaller, but apparently it's not clear-cut: https://www.quora.com/Which-element-is-bigger-an-atom-of-hydrogen-or-of-helium https://www.quora.com/Which-element-is-bigger-an-atom-of-hyd...