A gas giant made of 45% electrons would most likely have a highly charged and unstable atmosphere. With such a high concentration of electrons, the gas giant would constantly generate powerful electrical storms and lightning, creating a spectacular light show. The atmosphere would also be extremely reactive and prone to quickly changing its composition. Due to the abundance of electrons, the gas giant would likely have a very strong magnetic field, which could affect its surrounding environment and potentially disrupt the orbits of nearby moons and other celestial bodies. The intense electrical activity on the gas giant would make it a dangerous place for spacecraft to navigate, as the high levels of radiation and magnetic interference could pose significant hazards. Overall, a gas giant made of 45% electrons would be a visually stunning but extremely dangerous and inhospitable environment.