Which elements do not follow ther Octet Rule? Xenon Copper Helium Hydrogen

The elements that do not follow the Octet Rule are:<br /><br />1. **Helium (He)**: Helium has only one electron shell, which can hold a maximum of 2 electrons. Therefore, helium is stable with 2 electrons in its outer shell and does not follow the Octet Rule.<br /><br />2. **Hydrogen (H)**: Hydrogen has only one electron shell, which can hold a maximum of 2 electrons. Therefore, hydrogen is stable with 2 electrons in its outer shell and does not follow the Octet Rule.<br /><br />3. **Xenon (Xe)**: Xenon is a noble gas with a complete outer electron shell, making it stable and not needing to follow the Octet Rule.<br /><br />4. **Copper (Cu)**: Copper is a transition metal and often forms compounds where it does not achieve a full octet in its outer shell. For example, in copper(I) oxide (Cu2O), copper has an oxidation state of +1, which means it has only one electron in its outer shell, not following the Octet Rule.<br /><br />In summary, helium, hydrogen, xenon, and copper are elements that do not follow the Octet Rule.