does sperm die when it hits air

Sperm do not die immediately when they hit air. Instead, sperm typically lose viability and die within a few minutes to about half an hour after exposure to air. The main reason for this is that sperm need moisture to survive, and when semen dries out after hitting air, sperm die faster. Oxygen itself does not kill sperm, but exposure to air causes drying, which leads to sperm death. In warm, moist environments like inside the female reproductive tract, sperm can survive up to five days, but outside the body, their lifespan is much shorter due to drying and environmental conditions.