Final answer:
The three basic products ejected from active volcanoes are gases, ash, and lava. These include water vapor, carbon dioxide, sulfur dioxide, fragmented rock particles, and various types of lava flows, which can form extensive lava plains.
Step-by-step explanation:
The three basic products that are ejected from active volcanoes include various types of gases, ash, and lava. Most of the gas released is water vapor, but other gases such as carbon dioxide (CO₂), sulfur dioxide (SO₂), and other volcanic gases are common. Volcanic ash, which is a mixture of fine particles of fragmented volcanic rock and minerals (volcanic material), is often ejected high into the atmosphere during an eruption. Finally, hot silicate lava flows from volcanoes, ranging from slow-moving thick lava to rapid-flowing basaltic lava that can spread out to form lava plains. Notably, the largest known terrestrial eruptions, such as those that produced the Snake River basalts in the northwestern United States, are of this type.