Final answer:
The most important factors that determine a magma's viscosity are composition and temperature.
Step-by-step explanation:
The most important factors that determine a magma's viscosity are composition and temperature.
The original composition of the molten material and the cooling process of the molten material that formed the rock define the classification of igneous rocks. The composition of the rock refers to the minerals present, while the texture refers to features like mineral sizes or the presence of glass or holes in the rock.
In addition to composition, temperature also plays a significant role in determining a magma's viscosity. Higher temperatures lead to lower viscosity, making the magma more fluid, while lower temperatures result in higher viscosity, making the magma more viscous and resistant to flow.