Question

What is the silica content of magma that has a low viscosity??

Answer 1

For the answer to the question above, the answer is 
low silica content 
(basaltic magma)
or should I say the answer is Magma with high viscosity
I hope my answer helped you. Feel free to ask more questions. Have a nice day!

Answer 2

The viscosity of magma is directly related to the silica content. That being said, the viscosity of magma is higher when the silica content is also high and it is a low viscosity magma when the silica content is also low. The silica content of low viscosity magma is approximately 45 - 55 wt%.