How long does it take for volcano to form? by Ava

My question was long does it take for a volcano to form? I found out that it takes 10,000-500,000 years. Then I started to wonder, why does it take so long for volcanoes to form? First, I needed to know how volcanoes are formed then I would understand. First, they are formed by the movement of  tectonic plates. Next, a tectonic plate will sink into the mantle an become very hot. Next, the molten rock will make its way through the cracks.Then, as it makes its way through the cracks. Then, as it makes its way to Earth's surface we call it lava. Lastly, layer upon layer lava builds up and a volcano is formed. Then I knew there was a lot to do and it takes a long time. That is what I have learned!