Final answer:
The element with a mass approximately 4 times that of a hydrogen atom is Helium (He), with an atomic mass of about 4 amu.
Step-by-step explanation:
The element with a mass approximately 4 times that of an H atom is Helium (He). The mass of a hydrogen atom is about 1 atomic mass unit (amu), and helium, with an atomic mass of about 4 amu, fits this description. Helium's nucleus consists of 2 protons and usually 2 neutrons, summing up to a mass number of 4 (4(He) is the nuclear symbol for helium-4, with the element symbol He, the mass number to the top left is 4, and the atomic number to the bottom left is 2).
A comparison to illustrate this relationship can be shown through the isotope Lithium-6, which contains three protons, three neutrons, and three electrons. Its nuclear symbol is 6Li. This isotope of lithium has a mass that is roughly 6 times that of a hydrogen atom, reaffirming that helium, with a mass four times that of hydrogen, is indeed the element in question.