Year 3 Science · Rocks, fossils and soils · Summary

Year 3 Science Rocks, fossils and soils: summary and key words

Part of the Year 3 Science rocks, fossils and soils chapter. Chapter overview · whole chapter on one page

Chapter summary

Skill	Method
Kinds of rock	Compare rocks by colour, texture, layers, sparkly crystals and holes.
Hard and soft	A hard rock does not crumble when pressed gently; a soft rock crumbles.
Permeable	A material is permeable if water can soak into or pass through it; impermeable if it cannot.
Parts of soil	Soil is made from broken-down rock and organic matter, with air and water in the gaps.
Fair test on soil	Change only the type of soil, keep the water the same, measure the water collected, and find the mean.
Fossils	A fossil is the remains or a trace of something that lived long ago, kept in rock.
How fossils form	Remains are buried in sand or mud, layers build up, and the layers are squashed into rock.
Reading layers	In layers that have not been turned over, the bottom layer is the oldest and the top layer is the newest.

I can compare rocks by colour, texture, layers, sparkly crystals and holes
I can say whether a rock is hard or soft, and whether water can soak into it (permeable)
I can name the four parts of soil: broken-down rock, organic matter, air and water
I can read the results of a fair test on soil, and say what was changed and measured
I can say what a fossil is, and tell remains from traces
I can put the stages of fossil formation in order, and read the layers in a diagram

rock: a hard, natural material found in the ground
texture: how a rock or soil looks and feels, for example smooth, rough, crumbly or gritty
layer: one flat band of rock or soil, lying on top of or below others
permeable: a material that water can soak into or pass through
impermeable: a material that water cannot soak into or pass through
soil: the layer on top of the ground where plants grow, made from rocks and organic matter
organic matter: dead plants and animals, and their waste, which break down in soil
sediment: sand and mud that settle in layers, often in water
fossil: the remains or a trace of something that lived long ago, kept in rock
body fossil: a part of a living thing kept in rock, such as a bone, a tooth, a shell or a leaf
trace fossil: a sign that a living thing was there, such as a footprint kept in rock
fair test: a test where only one thing is changed, and everything else is kept the same
mean: the average of several results, found by adding them and dividing by how many there are