how many electrons does Helium need to have a full outer shell
The correct answer and explanation is:
Helium needs 2 electrons to have a full outer shell.
Helium is a noble gas, and like other noble gases, it has a stable electron configuration. It belongs to Group 18 of the periodic table, which contains elements that naturally have full outer electron shells. The outermost shell of helium, which is its only shell, can hold a maximum of two electrons. Therefore, when helium has two electrons, its outer shell is full, and it is chemically stable.
Helium’s electron configuration is 1s², meaning that its first and only electron shell contains two electrons. This is the maximum number of electrons this shell can hold, as the first shell is capable of holding only two electrons. Because of this, helium is chemically inert and does not readily form bonds with other elements, unlike elements that require more electrons to complete their outer shells.
Elements in other groups of the periodic table often need to gain or lose electrons to achieve a stable electron configuration, but helium already has a complete outer shell with two electrons. This makes helium one of the most stable elements and explains why it is found as a monoatomic gas in nature. It does not participate in chemical reactions to the same extent as other elements, making it highly non-reactive. This property of having a full outer shell with two electrons is the reason why helium, along with other noble gases like neon, argon, and xenon, is considered chemically inert.