How many electrons does Helium (He) have?
The correct answer and explanation is:
Helium (He) has 2 electrons. This can be determined from its atomic number, which is 2. The atomic number of an element tells you the number of protons in its nucleus, and in a neutral atom, the number of protons equals the number of electrons. Therefore, a neutral helium atom has 2 electrons.
Helium is a noble gas, and its electron configuration is 1s². This means that both of its electrons occupy the 1s orbital, which is the closest and lowest energy level to the nucleus. Because the 1s orbital can hold a maximum of two electrons, helium achieves a stable electron configuration with a full outer shell.
Helium’s full outer shell gives it unique properties, including its chemical inertness. Unlike other elements, which tend to form bonds to achieve a stable electron configuration, helium is already stable. This is one of the reasons why it is classified as a noble gas, a group of elements known for their lack of reactivity.
Since helium only has two electrons, it is one of the simplest atoms in the periodic table. The fact that helium has a full outer shell makes it highly stable and non-reactive. This stability also explains why helium is often used in applications like filling balloons and cooling systems, where non-reactivity is important.
To summarize, helium has 2 electrons, which are arranged in its 1s orbital, making it chemically stable and inert. Its electron configuration and its position in the periodic table help explain why it behaves the way it does in various chemical contexts.