Reference no: EM13190131

Lava is: 
1.always produced during any volcanic activity. 
2.molten rock that cools and hardens on Earth's surface. 
3.all the same chemical composition, whether it's rhyolite or basalt. 
4.the most life-threatening volcanic product of any eruption. 
5.all of the above are true.

Rhyolite lava: 
1. has more silica than basalt lava does. 
2.indicates the tendency for explosive activity. 
3.may freeze in the vent and emerge as a spine. 
4.may form a lava dome above the vent. 
5.all of the above are true.

Pick out the false statement. Carbon dioxide: 
1. is denser than air. 
2.is a common volcanic product that can suffocate life. 
3.is a toxic (poisonous) gas; even a little can kill you. 
4.was released at Lake Nyos, Cameroon, Africa, and killed many people. 
5.is released by magma as it rises and the pressure gets lower.

Mt. St. Helens erupted in 1980, sending out gas and pyroclastics. Geologists have found evidence of many eruptions of St. Helens, dating back 37,000 years. The mountain is huge and is composed of layers of lava and pyroclastics. Which of the following is most likely true? 
1. When lava flows, it will be basalt. 
2.It will not erupt again. 
3.It's a stratovolcano (or composite cone). 
4.It's on a transform plate boundary. 
5.It's a cinder cone.