Hot and Cold (Heat)

• Heat always flows from a hotter object to a colder object.
• A thermometer is used to measure how hot or cold something is.
• Ice is a cold solid that melts into water when it absorbs heat.
• Wearing a woollen sweater keeps us warm by trapping body heat.
• Metal spoons feel hotter than wooden spoons in hot tea, because metal conducts heat faster.

Level 1 — Core idea

Verbal: Heat moves on its own from a hotter object to a colder one until both become equally warm.

Symbolic: hot object → heat flows → cold object (until both are equally warm)

Visual: Dip a metal spoon and a wooden spoon in hot tea — the metal spoon warms up faster in your hand.

Level 2 — Going deeper

Think about where you see this idea in daily life at home and school — noticing it around you makes the concept easier to remember.

NCERT anchor

NCERT Looking Around 3 'keeping warm' chapter explores wool, sweaters, and why some materials trap heat better.

You place an ice cube on a warm plate. What happens, and why?

Step 1 — The plate is warmer than the ice
Step 2 — **Heat flows** from the plate into the ice
Answer: **The ice melts as it absorbs heat from the plate**

Why does a metal spoon in hot tea feel hotter to touch than a wooden spoon in the same tea?

Step 1 — Metal lets heat pass through it quickly
Step 2 — Wood lets heat pass through it slowly
Answer: **Metal conducts heat faster, so it feels hotter**

• Which way does heat flow — hot to cold, or cold to hot?
• What is a thermometer used for?
• Why does ice melt when left on a warm plate?
• Stretch: Why do we wrap food in a cloth to keep it warm for longer?

Revision tip: Remember: heat always moves from the hotter side to the colder side, never the other way.

Open the Practice tab for graded questions on Hot and Cold (Heat).