Changes in Water · Mati Learning Hub

LESSON 3.1 · SC.3.P.9.1

Heating Water

Learning goal: Describe melting, boiling, and evaporation caused by heating.

What to know

Adding heat can raise water’s temperature or change its state. During a state change, the water is still made of the same tiny water particles.
Melting changes solid ice into liquid water. Pure water melts near 0°C / 32°F under ordinary conditions.
Evaporation changes liquid water into invisible water vapor at the surface. It can happen below the boiling point, which is why a puddle can slowly disappear.
Boiling is rapid vaporization throughout a liquid. Near sea level, pure water boils around 100°C / 212°F. Bubbles form inside the water, while steam-like mist above it is made of tiny liquid droplets.

WATCH & NOTICE

States of Matter for Kids

From Learn Bright

Pause when water changes state and name the process before the video does.

Open video on YouTube ↗

Think like a scientist

Sunlight can slowly evaporate a puddle far below 100°C / 212°F and without bubbles. Strong heating can bring water to its boiling point and make vaporization happen throughout the container.

INTERACTIVE HEATING LAB

Add energy and watch the water

Move the heat control slowly. The model shows which evidence a scientist would look for as ice melts, liquid warms, surface evaporation continues, and water finally boils.

Meltingsolid → liquidEvaporationliquid → gas at the surfaceBoilingliquid → gas throughoutWater vaporwater as an invisible gas

Heat added 20%

Approximate water temperature0°C / 32°F

🧊

Melting begins

Some solid ice is changing into liquid water.

Evidence to notice

Ice pieces become smaller and liquid collects around them.

Evaporationsurface only

Can happen at many temperatures. It is usually slow and has no boiling bubbles.

Boilingthroughout the liquid

Fast vaporization. Bubbles form within the water and rise to the surface.

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LESSON 3.2 · SC.3.P.9.1

Cooling Water

Learning goal: Describe freezing and condensation caused by cooling.

What to know

Cooling means thermal energy moves away from the water. Its temperature may fall, and enough cooling can change its state.
Freezing changes liquid water into solid ice. Pure water freezes near 0°C / 32°F under ordinary conditions.
Condensation changes invisible water vapor into visible liquid droplets when the vapor meets a cooler surface or cooler air.
Drops on the outside of a cold cup come from water vapor already in the surrounding air. A dry, uncracked cup does not leak water through its wall.

WATCH & NOTICE

States of Matter for Kids

From Learn Bright

Pause when water changes state and name the process before the video does.

Open video on YouTube ↗

Think like a scientist

An ice-water cup near 0°C / 32°F cools nearby air, so water vapor can condense outside. In a freezer below 0°C / 32°F, enough cooling changes liquid water inside into solid ice.

INTERACTIVE COOLING LAB

Remove energy: droplets first, ice later

Move the cooling control. Watch two related examples: water inside a container can freeze, while water vapor in the air can condense onto its cold outside surface.

Coolingthermal energy moves awayCondensationgas → liquidFreezingliquid → solidStatesolid, liquid, or gas

Cooling amount 15%

Approximate water temperature34°C / 93°F

💧

Liquid water

The water is cooling, but it is still liquid.

Where do outside drops come from?

Water vapor in the surrounding air touches the cooler cup and becomes liquid. It does not pass through the cup.

•• •• •Gasfar apart, moving freely

cooling →

••••••Liquidclose, sliding past

more cooling →

•••
•••Solidfixed arrangement

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LESSON 3.3 · SC.3.P.9.1

Follow the Change

Learning goal: Identify water’s state and the process connecting two states.

What to know

Identify the starting state and ending state before naming the process: solid, liquid, or gas.
Heating can cause solid → liquid (melting) and liquid → gas (evaporation or boiling). Cooling can cause gas → liquid (condensation) and liquid → solid (freezing).
Evaporation and boiling have the same state change but different evidence: evaporation occurs at the surface; boiling occurs throughout the liquid with bubbles.
State changes are reversible. Water can travel through the cycle again and again without becoming a different substance.

WATCH & NOTICE

States of Matter for Kids

From Learn Bright

Pause when water changes state and name the process before the video does.

Open video on YouTube ↗

Think like a scientist

An ice cube becoming a puddle is melting. A bathroom mirror becoming dotted with water is condensation. Name the evidence and the two states—not only whether the object feels hot or cold.

INTERACTIVE WATER PATH

Start state + end state = process name

Choose a real-world change. Follow its path through the state diagram, then read the evidence that proves which process occurred.

Solidkeeps its own shapeLiquidflows and takes container shapeGasspreads to fill available spaceReversibleable to change back

🧊Solid

💧Liquid

〰️Gas

🔍

CHOOSE AN EXAMPLE

Trace a change

First name the beginning and ending states. Then choose the process.

Water remains water. Melting, freezing, evaporation, boiling, and condensation are physical changes. The state changes, but a new substance is not created.

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What to know

States of Matter for Kids

Think like a scientist

Add energy and watch the water

What to know

States of Matter for Kids

Think like a scientist

Remove energy: droplets first, ice later

What to know

States of Matter for Kids

Think like a scientist

Start state + end state = process name

Trace a change

Unit 3 benchmark map