Very varied. Some erupt every few decades, some are dormant for centuries.
it was the lave
On average, there are about 50-70 volcanic eruptions per year worldwide. The frequency of eruptions can vary depending on the activity level of the particular volcano. Some volcanoes may not erupt for decades, while others may have frequent eruptions.
Yes, they often erupt again.
strato
very very hot
Öræfajökull
It depends, a volcano can erupt once and never erupt again. Or, a volcano can erupt multiple times a day.
Never.
the crust is hard liquid magma (lava)
As many as it wants. Some volcanoes erupt often, some infrequently
The correct spelling is volcano (singular) or volcanoes (plural).
Mt.vesuvius does errupt often. hope this helped!