The simplest atom contains one proton and one

Electron

Explanation: The element hydrogen has the simplest atoms, each with just one proton and one electron. The proton forms the nucleus, while the electron orbits around it. All other elements have neutrons as well as protons in their nucleus, such as helium

they emit helium gas that attaches to nearby planets.

they remove low-mass elements from the planets’ crust.

they cause nuclear fusion inside the inner core of planets.

they produce heavy elements such as iron and gold.

explanation:

i think it is true since you can test the answer and can use observations to complete it.