Here's why:
* Electron Energy Levels: Electrons in atoms exist in specific energy levels. These levels are like "shells" around the nucleus, with higher numbered shells representing higher energy levels.
* Oxygen's Electron Configuration: Oxygen has an atomic number of 8, meaning it has 8 electrons. Its electron configuration is 1s² 2s² 2p⁴. This means:
* The first energy level (n=1) has 2 electrons in the 1s orbital.
* The second energy level (n=2) has 6 electrons, 2 in the 2s orbital and 4 in the 2p orbitals.
* Distance from the Nucleus: Electrons in higher energy levels are further from the nucleus. The further an electron is from the nucleus, the less tightly it is bound and the more energy it possesses.
Therefore, the electrons in the second level of oxygen are further from the nucleus and experience a weaker attraction to the positively charged nucleus, resulting in higher energy.
