How can rocks change? Unit:8 Lesson: 1

Water and wind can wear down rocks.

Erosion happens when worn down rocks are carried away.

It may happen so slowly that you can’t see.

When water or ice rubs against rock, it wears away at the rocks.

Water and wind can move small rocks.

These rocks bump into each other and break off into smaller pieces.

Lesson checkpoint Check yes or no Yes No Water and wind can wear down rocks. Water and wind can’t move small rocks. Erosion happens when worn down rocks and carried away.

8-2: How can soil and sand change? Bits of rock that wear away from bigger rocks become soil and sand.

Water can erode soil and sand. Heavy rain can wash soil away.

Wind can also erode soil and sand. Strong wind can soil and sand away. This may make a dust storm.

Plants help keep soil and sand from eroding. Plant roots hold soil and sand in place.

Lesson checkpoint Check yes or no Yes No 1- tiny rocks that wear away from bigger rocks become soil and sand. 2- people and animals breathe air. 3- plant roots don’t hold soil in place.

B- answer the following 1-what may form soil and sand? 2- how can plants help stop erosion?

A- Draw a picture of plant roots that hold soil.

Homework C-write about how water and wind change Earth.

8-3: what are fossils? Fossils are what is left of living things from the past.

Some fossils are prints of plants or animals.

Fossils Other fossils are part of things that were once lining. These part can be bones or teeth

Fossils can be Foot prints, Tracks or nests that animals left behind.

Lesson checkpoint Check yes or no Yes No 1- fossils are what is left of living thing from the past. 2- fossils are prints of animals only. 3- foot prints tracks or nests that animals left behind.

B- answer the following 1- what are fossils? 2-list three kinds of fossils?

Homework C- write about why fossils are important?