Here's why:

* Felsic lava is high in silica content (SiO2), which makes it very viscous and thick. This viscosity traps gases within the magma, building up pressure until a violent eruption occurs.

* Mafic lava, on the other hand, is low in silica content and much more fluid. This allows gases to escape easily, resulting in less explosive eruptions.

Examples of felsic lava:

* Rhyolite: This is the most silica-rich lava and can produce extremely explosive eruptions.

* Dacite: This is slightly less silica-rich than rhyolite but can still produce powerful explosions.

Note: While felsic lava is most commonly associated with explosive eruptions, other factors can also contribute to explosiveness, such as:

* Water content: Magma with a high water content can be very explosive, regardless of its silica content.

* Pressure: Rapid decompression can lead to explosions even in mafic lava.

Therefore, while felsic lava is the most likely culprit in an explosive eruption, it's important to remember that other factors play a role as well.