Was gun powder invented in the song or tang dynasty?

It is a little complex. Some people say it was invented during the Sui and Tang Dynasties. Sometime say that it was invented during te Han Dysnasty. Anyway, tjhe historic records show that it was first invented inadvertently by alchemists while attempting to make an elixir of immorality. At the end of the Tang Dynasty, gunpowder was being used in military affairs. During the Song and Yuan Dynasties, frequent wars spurred the development of cannons, and fire-arrows shot from bamboo tubes.