What are the three major factors controlling the viscosity of magmalava?

The three major factors controlling the viscosity of magma and lava are temperature, composition, and gas content. Higher temperatures typically decrease viscosity, while cooler temperatures increase it. The chemical composition, particularly the silica content, significantly influences viscosity; higher silica levels result in more viscous magma. Additionally, the amount of dissolved gases affects viscosity, with more gas leading to lower viscosity due to the formation of bubbles that reduce the magma's thickness.