Grade 3 · Science · Unit 9 of 10
Wind, Water & Ice
How the land changes shape
What your child practises
How wind, water and ice break rock down (weathering) and carry it away (erosion), slowly changing the shape of the land, and how plants and windbreaks protect soil.
Ontario Curriculum expectation: E2.4 · erosion by wind, water and ice, and how plants help protect soil
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
When a glacier melts back, what does it leave behind?
🧊- a field of seashells
- a new volcano
- piles of rocks and soil it carried
Show answer
piles of rocks and soil it carried
Hint: Glaciers carry rocks and soil as they move. When the ice melts, the rocks stay behind.
Question 2
How fast do weathering and erosion usually change the land?
⏳- only at night
- slowly, over many years
- in one second
Show answer
slowly, over many years
Hint: Most changes are slow. It can take thousands of years for a river to carve a canyon.
Question 3
How does a river make a canyon? Put the steps in order.
- 🏞️a river flows over rock
- 💧the water carries away tiny bits of rock
- 🏜️a deep canyon forms
- ⏳over many years, the river cuts deeper
Show answer
a river flows over rock → the water carries away tiny bits of rock → over many years, the river cuts deeper → a deep canyon forms
Hint: Moving water carries away tiny bits of rock. Over many, many years, the river cuts deeper and deeper.
Question 4
How does a glacier change the land?
🏔️- it makes the land float
- it scrapes and carves rock as it slowly moves
- it builds volcanoes
Show answer
it scrapes and carves rock as it slowly moves
Hint: A glacier is a huge, slow river of ice. It pushes rocks and carves out valleys.
Question 5
Which is an example of weathering, not erosion?
🔨- ice splitting a rock into pieces
- a river carrying mud to the ocean
- wind carrying sand away
Show answer
ice splitting a rock into pieces
Hint: Weathering breaks rock where it is. Erosion carries pieces somewhere else.
Question 6
What is changing the land: wind, water or ice?
Sort into: 🌬️ wind · 🌊 water · 🧊 ice
- 🏜️blows sand into dunes
- 🏞️a river carves a canyon
- 🏖️waves wear away a cliff
- 🌾blows dry soil off a field
- ❄️frozen water splits a rock
- 🏔️a glacier carves a valley
Show answer
🌬️ wind: blows sand into dunes, blows dry soil off a field · 🌊 water: a river carves a canyon, waves wear away a cliff · 🧊 ice: frozen water splits a rock, a glacier carves a valley
Hint: Wind blows sand and dust. Water flows, splashes and washes things away. Ice freezes in cracks, and glaciers scrape the land.