Science Polar Regions Conceptual 7–9 yrs

Ice & States of Matter

冰与物质状态

Description

Understand ice in different forms and states of matter — sea ice forms when ocean water freezes (it's salty and relatively thin), glacial ice forms from compacted snow over centuries (fresh water, very thick), and icebergs break off from glaciers and float in the sea; know that water exists as solid (ice), liquid (water), and gas (water vapour), and that salt lowers the freezing point of water

Mastery Evidence

✓ Distinguish between sea ice (frozen ocean, salty, thin) and glacial ice (compacted snow, fresh water, thick)
✓ Explain that icebergs break off from glaciers and float because ice is less dense than liquid water
✓ Describe the three states of water (solid, liquid, gas) and explain that salt lowers the freezing point

Assessment Prompt

Can your child explain the difference between sea ice and glacier ice, and describe how water changes between solid, liquid, and gas — maybe by doing a simple freezing experiment with salt and fresh water?