Matter Chapter Notes | Eureka Plus Class 5: Book Solutions, Notes & Worksheets PDF Download

Introduction

In our previous class, we learned about something very important called "matter." Let's recall some facts and learn even more about it. Everything around us, like the air we breathe, the juice of a pineapple, raindrops, and even the mighty sun, is made up of matter. If we can see it, touch it, or smell it, it's matter.

Matter - Mass and Volume

Definition of Matter: Matter has mass and volume. Mass is the amount of matter in an object, and volume is the space it occupies.

Molecules and Atoms

• Building Blocks of Matter: Matter is made up of tiny building blocks called molecules.
• Atoms in Molecules: Molecules are made up of even smaller particles called atoms. For example, water (a type of matter) is made of two hydrogen atoms and one oxygen atom.
• Ball and Stick Models: Scientists use models to understand molecules. In these models, atoms are like colored beads, and they show how atoms join together to form molecules.

Elements

• Definition of Elements: A substance made of only one kind of atom is called an element.
• Examples of Elements: Oxygen, nitrogen, hydrogen, and gold are examples of elements. Each element has a symbol, like 'H' for hydrogen and 'O' for oxygen.

Compounds

• Definition of Compounds: A substance made of more than one kind of atom is called a compound.
• Examples of Compounds: Carbon dioxide, water, and table salt are examples of compounds. They have different types of atoms in their molecules.

The Three States of Matter

• Solid, Liquid, Gas: Matter can exist in three states - solid, liquid, and gas.
• Water's Exception: Unlike most substances, water can exist as a liquid and gas at room temperature.

What Determines the State of Matter?

• Force of Attraction: The way molecules are arranged and the force holding them together determine the state of matter.
• States of Matter Explanation:
  • Solid: Strong force, molecules tightly packed.
  • Liquid: Weaker force, molecules can move but stay close.
  • Gas: Very weak force, molecules can move freely and spread out.

Changing States of Matter

Heating and Cooling: Heating makes molecules move apart, changing a solid to a liquid and a liquid to a gas. Cooling does the opposite.

Changes Around Us

• Physical Change: Temporary change, doesn't create a new substance. Example: Melting wax.
• Chemical Change: Forms new substances, usually irreversible. Example: Sugar turning into carbon when heated continuously.