Key words:

Rocks

• Rock

• Igneous rock

• Sedimentary rock

• Metamorphic rock

Minerals

• Mineral

• Hardness

• Lustre

• Streak

Soil

• Soil

• Humus

• Topsoil

• Subsoil

• Bedrock

• Weathering

• Erosion

  
  

FUN FACT

Some rocks can actually float on water!There is a rock called pumice that has tiny air holes inside it, making it so light that it floats like a sponge.

Definition:

Rock – A natural solid found on Earth.Igneous rock – Rock formed when melted rock cools and hardens.Sedimentary rock – Rock made from layers of sand, mud, and small pieces pressed together.Metamorphic rock – Rock changed by heat and pressure.

Mineral – A pure, natural substance found in rocks.Hardness – How easily a mineral can be scratched.Lustre – How shiny a mineral is.Streak – The colour of a mineral’s powder.

Soil – The top layer of Earth where plants grow.Humus – Rotten remains of plants and animals in soil.Topsoil – The top, nutrient-rich layer of soil.Subsoil – The layer below topsoil with less humus.Bedrock – The hard rock layer deep underground.Weathering – Breaking rocks into small pieces.Erosion – Movement of soil by wind or water.