Answer;
H- (negatively charged hydrogen ion)
Step-by-step explanation;
The hydrogen ion has the same electron configuration as an atom of Helium. -Hydrogen ion is formed when a hydrogen atom loses or gains an electron. A positively charged ion is formed when hydrogen atom loses an electron (remaining with zero electrons) while a negatively charged ion (H-) is formed when a hydrogen atom gains an electron thus having 2 electrons.
-Helium atom has two electrons, therefore, it is similar with an negatively charged hydrogen.