Here's why:
* Oxygen is a highly electronegative element, meaning it tends to gain electrons.
* Oxides are compounds formed when oxygen combines with another element.
* When oxygen gains two electrons, it forms an oxide ion with a charge of -2 (O-2).
Examples of oxide compounds:
* Carbon dioxide (CO2): Contains one carbon atom and two oxygen atoms.
* Iron oxide (Fe2O3): Contains two iron atoms and three oxygen atoms.
* Sodium oxide (Na2O): Contains two sodium atoms and one oxygen atom.
Remember, the chemical formula for oxides can vary depending on the element that oxygen combines with.
