What element is this? how do you know?
pls

The element is helium.

We know this because if you look at the periodic table, Helium has an atomic number of 2, meaning that it has 2 protons.

To solve for neutrons, we simply subtract the mass by its' number. We can round 4.003 to 4, showing that it has 4 - 2 = 2 neutrons

i believe that it is a exoplanet