Why does helium only have 2 electrons?
Answer: Helium only has 2 electrons due to its atomic structure and the filling of electron shells.
Explanation: The atomic structure of an element is determined by its atomic number, which represents the number of protons in its nucleus.
Helium (He) has an atomic number of 2, indicating that it has 2 protons in its nucleus. In a neutral atom, the number of electrons is also equal to the number of protons. Therefore, helium has 2 electrons.
The filling of electron shells follows the Aufbau principle, which states that electrons fill the lowest energy levels (shells) first before moving to higher energy levels.
In the case of helium, the first electron shell (1s) can hold a maximum of 2 electrons. As a result, helium’s electron configuration is 1s², with both electrons occupying the 1s subshell.