Atoms, just like people, are always looking to be happy. But unlike us, their happiness comes from having 8 valence electrons, meaning 8 electrons in their outermost shell. In the first shell, atoms are able to hold 2 electrons, in the second 8, and in the third 8 as well. To be happy, atoms have two options, they can either try gaining electrons so as to achieve 8 in their second or third shell, or they can give away electrons to other atoms that need them more so as to only fill two shells rather than all three.
One day Oxygen (O) was trying to decide on an outfit to wear to school, but there was a problem. Nothing seemed to fit right! She had thought she was in perfect shape. Her protons and neutrons were looking good and she was pretty confident, until today. She looked down. "OH NO!" she exclaimed! "I completely forgot! I'm so unhappy.." What she saw when she looked down was an unfinished 3rd shell and she started to panic. She threw on her baggiest clothes, as she was extremely embarrassed about her homely appearance. Walking through school seemed like such a disgrace. She could feel people's glares on her back. "This is the worst day ever..." she thought. She first went to her best friend Nitrogen (N). "Do you think you could lend me an electron or two? I'm short two and it's making me so upset!" Nitrogen grimaced. "Well actually I just gained three from Boron (B) and I'm really not willing to give any up right now. I'm so sorry Oxygen you know normally I would." Oxygen shrugged. She understood where Nitrogen was coming from. "I'll ask around for you though!" Nitrogen offered. Oxygen pouted. "It's okay! Thanks anyway Nitrogen!" She tried to sound sincere. Oxygen was so dismayed. If Nitrogen wouldn't help her, it seemed nobody would. That is, until she saw Magnesium (Mg). She too was walking around in her baggiest clothes, sporting a frown across her nucleus. "Excuse me? Magnesium? I have a question." Oxygen introduced herself and attempted to find the words to describe her dilemma. "Well," she started. "I noticed that you too are wearing baggy clothes... and I was wondering if it's because you need two valence electrons like me?" Magnesium looked down, obviously embarrassed. "Actually I need 6. Unless I just give away two, which would probably work as well. I really just need to reach 8!" Oxygen's smile could have rivaled a hyena's. "Perfect!!" she proclaimed. "We're in luck! I need two to reach 8 and you need to get rid of two!" Magnesium grinned. "Are you thinking what I'm thinking?" She questioned. "I don't know... Maybe? What exactly are you thinking?" Oxygen asked. "Well, I was thinking I could give you my two 3rd shell electrons! I don't need them, and I don't think anyone is likely to give up 6, so I might as well just give you mine and reach 8 in the second shell!" Oxygen looked up at Magnesium. "That's a great idea!!! Are you sure you don't mind?" "Positive." Magnesium replied. "I'd be happy to give you them." Magnesium pulled off the two electrons and handed them to Oxygen. Neither of them could help beaming at their new-found friendship and filled shells.
