Rocks

Q What do we get from the earth?A: We get rocks, metals, natural gases, coal and oils from the earth.

Q What are rocks?A: Rocks are natural materials. Small pieces of rocks are called stones, pebbles and

gravel.

Q What are rocks made up of?A: Rocks are made up of tiny grains. The grains can be different colour, shape and size.

Q Why do rocks have different colours?A: The rocks contain minerals which give them different colours.

Q What are uses of rocks?A: During Stone Age rocks were used as tools and weapons. Now rocks are used to make

houses, roads, roof covering. Precious stones are used to make ornaments.

Q Why is rock a good material for making building and bridges?A: Because rock is a very strong material.

Q What are stones? What is their use?A: Stones are small pieces of rocks. They are used to make walls, houses and paths.

Q What are pebbles? What is their use?A: Small stones are called pebbles. They are used to decorate garden fountains and

pots.

Q What are gravels? What is their use?A: Very small stones are called gravels. They are used to make roads and railway

tracks.

Q Name types of rocks.A: 1) Sedimentary 2) Igneous 3) Metamorphic

Q How do sedimentary rocks form? Give examples.A: Materials that settle down to the bottom of a liquid and eventually become solid.

Trees become coal, sand become sandstone and chalk become limestone.

Q What are the uses of sedimentary rocks?A: it is used to make statues and building stones.

Q How do igneous rocks form? Give examples.A: They form from the cooling of magma after volcanic eruption. Outer lava becomes

basalt and inner lava becomes granite.

Q What are the uses of igneous rocks?A: It is used to make road stone and construction.

Q How do metamorphic rocks form? Give examples.A: They are either sedimentary or igneous which are changed to another form from

heat and pressure inside the earth. Lime stone become marble and clay become slate.

Q What are the uses of metamorphic rocks?A: It is used to make roofing industry and decorative products.

Q What are porous or permeable rocks?A: Rocks that absorb water, are called porous rocks. Example sandstone.

Q What are non-porous or impermeable rocks?A: Rocks that do not absorb water, are called non-porous rocks.

Example marble and granite.

Q What are fossils?A: Fossils are remains of animals that are preserved in sedimentary rocks.

Q What does the rock cycle show?A: Rock cycle shows how igneous rock forms sedimentary or metamorphic rock. Which

eventually melt and become igneous rock again.

Q Show rock cycle.

Q Make a table to show properties of different rocks.

Type of rock Type of grain

Mode of formation

Ease of breaking

Fossil remains

Examples

Igneous Grains not lined up

Cooling of magma

Hard, difficult to split

Absent Basalt, Granite, Pumice

Sedimentary Rounded grains not lined up

Deposition of particles

Often soft and crumbly

May be present

Sandstone, Limestone, Clay

Metamorphic Grains often lined up

Heat and pressure on other rocks

Hard but may split into layers

Absent Marble (from limestone), Slate (from clay)

http://www.onegeology.org/extra/kids/earthprocesses/weathering.html