Answer:
Helium, He is the most lightest among the given four elements. As the molecular mass of helium,He is about 4.002602 u. It is considered the second most lightest element inside the periodic table after the hydrogen,H atom which is the lightest of all.
Step-by-step explanation:
- Velocity dependence upon the molecular weight of the element:
The molecular weight of the different elements gives them the very specific features including the ability to travel fast in a given space. While the helium,He is considered one of the lightest elements in the universe so, it has a greater velocity among the four options.
A person with less weight will run much faster as compared to a person having more weight.