Helium is in group 18 of the periodic table. How is helium different from other elements in this group helium atoms have two electrons well atoms of the other elements have 18 electrons helium atoms have full outer energy level while atoms of the other elements in the group do not have full outer energy levels helium Adams have two valence electrons while atoms in the other group. I'll have eight valence electrons helium Adams and valence electrons in the first energy level while the atoms in the other electrons Elements in the group have electrons of the second energy level

Answer 1

Helium is indeed unique among the elements in Group 18 (the noble gases) of the periodic table. Here are key differences between helium and the other noble gases:

1. Electron Configuration:

   • Helium has two electrons (1s²), which means its outermost energy level (energy level 1) is full.
   • In contrast, other noble gases like neon (10 electrons, 1s² 2s² 2p⁶), argon (18 electrons, 1s² 2s² 2p⁶ 3s² 3p⁶), and so on, have their outer energy levels filled with eight electrons, completing the octet rule.

2. Valence Electrons:

   • Helium has 2 valence electrons (in its first energy level).
   • The other noble gases have 8 valence electrons in their outermost shells (typically the second energy level or higher).

3. Energy Levels:

   • Helium's valence electrons are in the first energy level, which can hold a maximum of 2 electrons.
   • The other noble gases have their valence electrons in higher energy levels (second, third, etc.), which can hold more electrons, allowing them to achieve the octet configuration.

These differences contribute to helium's distinct chemical properties. Even though helium is a noble gas, it does not conform to the typical behavior seen in heavier noble gases, particularly regarding its atomic structure and interactions with other elements.