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Matter and Materials - States of Matter

Grade 3ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Matter is defined as anything that has mass and occupies space. Everything we see, touch, or feel is made of matter.

Matter exists in three primary states: Solids, Liquids, and Gases.

Solids have a fixed shape and a fixed volume because their particles are packed very closely together.

Liquids have a fixed volume but no fixed shape. They take the shape of the container they are kept in. For example, water (H2OH_2O) or milk.

Gases have neither a fixed shape nor a fixed volume. They fill the entire space available to them, like air or steam (H2OH_2O in gaseous state).

Change of State: Matter can change from one form to another by heating or cooling. Melting is the process where a solid turns into a liquid, while freezing is when a liquid turns into a solid.

Evaporation is the process of a liquid changing into a gas upon heating, and condensation is the process of a gas changing into a liquid upon cooling.

📐Formulae

H2O (Water)H_2O \text{ (Water)}

SolidHeatingLiquidHeatingGas\text{Solid} \xrightarrow{\text{Heating}} \text{Liquid} \xrightarrow{\text{Heating}} \text{Gas}

GasCoolingLiquidCoolingSolid\text{Gas} \xrightarrow{\text{Cooling}} \text{Liquid} \xrightarrow{\text{Cooling}} \text{Solid}

💡Examples

Problem 1:

Identify the state of matter for the following: A wooden block, honey, and oxygen gas.

Solution:

Wooden block is a Solid; Honey is a Liquid; Oxygen is a Gas.

Explanation:

The wooden block has a fixed shape (Solid). Honey flows but has a fixed volume (Liquid). Oxygen spreads to fill any container (Gas).

Problem 2:

Rohan left an ice cube (H2OH_2O) on the table. After some time, it turned into a small puddle of water. What process took place?

Solution:

Melting

Explanation:

When ice (solid) absorbs heat from the surroundings, it changes its state into water (liquid). This process is called melting.

Problem 3:

If you pour 200 ml200\text{ ml} of milk from a bottle into a glass, will the volume change?

Solution:

No, the volume remains 200 ml200\text{ ml}.

Explanation:

Liquids have a definite volume, even though they change their shape to match the container they are in.

States of Matter - Revision Notes & Key Formulas | ICSE Class 3 Science