Question

which one of the following shows the correct order (left to right) of decreasing magma viscosity? basalt, andesite, rhyolite basalt, rhyolite, andesite andesite, rhyolite, basalt rhyolite, andesite, basalt question 2 2 pts the viscosity of magmas increase with increasing % of silica. true false

Explanation:

For the first question:

• Viscosity of magma is related to silica content. Higher silica content means higher viscosity.
• Rhyolite has high silica content (about 65 - 77%), andesite has moderate silica content (about 52 - 63%), and basalt has low silica content (about 45 - 52%).
• So, the order of decreasing viscosity (highest to lowest) is rhyolite (high silica - high viscosity), andesite (moderate silica - moderate viscosity), basalt (low silica - low viscosity).

For the second question:

• As per the relationship between silica content and magma viscosity, viscosity of magmas increases with increasing % of silica.

Answer:

First question: rhyolite, andesite, basalt
Second question: True