Yes, plants do give off oxygen. Through the process of photosynthesis, plants use light energy to convert carbon dioxide and water into glucose (food) and oxygen. The oxygen produced during photosynthesis is released into the atmosphere as a byproduct. This process is vital for maintaining the oxygen levels in our atmosphere, as it is estimated that plants produce around 70% of the Earth’s oxygen. Additionally, indoor plants such as the snake plant and peace lily mentioned in the available information are known for their ability to remove toxins from the air, further improving indoor air quality.