Question 1

how did rocks get hard

Accepted Answer

The chemical bonds that hold atoms together in these minerals are stronger in some than in others, and the atoms themselves determine which bonds are stronger than others. Stronger bonds make for stronger minerals and, thus, harder rocks.

Question 2

how can you figure out the type of rock just by looking at it?

Accepted Answer

Unless an expert geologist that has memorized the type of rock by its features looks at a rock, you can't just infer the type of rock by looking at it.

Question 3

Why go through so much trouble to study how old a rock is?

Accepted Answer

It’s hard to answer the basic questions of geology without knowing the ages of rocks. People want to know how long life has existed on Earth and what the earliest lifeform was. We’ve answered those questions by dating rocks containing fossils. Life has existed at least as long as the oldest fossil. Wouldn’t you like to know when dinosaurs lived? We’ve answered that by dating the rocks that contain dinosaur fossils. We’ve determined the age of Earth by dating meteorites. We know when the moon formed by dating moon rocks. When did the Hawaiian Islands form? Which one of the islands is the oldest? Both questions were answered by dating rocks. We can also use our dating methods to answer questions about geologic hazards. When was the last eruption of the Yellowstone Supervolcano? How frequently has Yellowstone erupted? All of these questions have been answered through methods developed by geologists to determine the ages of rocks. They are powerful techniques that answer these questions and so many more.

Question 4

is sand sediment

Accepted Answer

Sand is sediment. More specifically, sand is a size of sediment. Other common sediment sizes that you may have heard of are clay, silt, and gravel. Sand is larger than clay and silt, but smaller than gravel.

Question 5

is it possible for a rock that used to be a mountain but became a rock years later turn back into a mountain?

Accepted Answer

Mr. ultimate rizz, thank you for raising your question. "If you seek to understand, you seek knowledge... "
To answer your question: let's imagine that a big rock broke off from a mountain somewhere. It falls deep into the valley. Perhaps, hundreds of millions of years later, that land in the valley will be pushed upwards on the earth's crust. If the rock had stayed in that rising place, it could be pushed up to form part of a new mountain.

Question 6

i dont understand the magama and lava part

Accepted Answer

Magma is lava when it is underground, when the magma gets shot out of a volcano, or when the magma comes out of the earth's surface, it becomes lava

Question 7

how Sedimentary rocks form into Igneous rocks

Accepted Answer

If a sedimentary rock is subjected to intense heat it will melt. Once it rises up and cools down, it will form an igneous rock

Question 8

Is a rock from space?

Accepted Answer

Some rocks came from space, but most rocks that we find on earth  are from mountains and the ocean. Sometimes when certain molecules bond they make a rock like structure and form. Rocks that are from space, and end up on earth, usually come here by an astroid (like the ones that killed the dinosaurs), or by humans (like the astronauts that go to the moon and bring rocks and particles back). But if you go back to when the solar system was created, you'll learn that it was a large cloud of rocks and dust that formed all the planets. So the super old rocks that are on earth most likely came from space (but they would have to be older than 4.5 billion years).

Question 9

So what are the types of rocks we see in day-to-day life, like pebbles? Metamorphic?

Accepted Answer

maybe it's the sediment.

Question 10

why is the rock cycle important?

Accepted Answer

It's important because it can help grant insight to the history of our planet, teaches us about how humans are impacted by natural disasters, and even provides resources that we use every day (such as salt and diamonds for drill-bits).

Course: Middle school Earth and space science - NGSS > Unit 4

The rock cycle

Key points:

Want to join the conversation?