Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Matter is defined as anything that has mass and occupies space (volume).
Matter is made up of very tiny particles called molecules. These molecules are so small they cannot be seen with the naked eye.
Solids: Molecules are very closely packed. They have a definite shape and a definite volume. For example, a wooden block.
Liquids: Molecules are less closely packed than in solids. They have a definite volume but no definite shape, taking the shape of the container. For example, (water).
Gases: Molecules are very far apart with large spaces between them. They have neither a definite shape nor a definite volume. They fill the entire space available to them.
The space occupied by an object is called its Volume (), and the quantity of matter contained in it is called its Mass ().
Change of State: Matter can change from one state to another on heating or cooling. For example, .
📐Formulae
💡Examples
Problem 1:
A wooden block has a mass of and occupies a space of . What property of matter does the represent?
Solution:
Volume ()
Explanation:
The space occupied by any object is known as its volume. In this case, the wooden block occupies of space, which is its volume.
Problem 2:
Why can we smell a perfume sprayed in one corner of a room from the other side?
Solution:
Diffusion of Gas
Explanation:
Perfume is a gas, and gas molecules move very fast in all directions because there is a lot of space between them. This movement allows the scent to spread or diffuse throughout the room.
Problem 3:
What happens to the molecules of water when it turns into ice at ?
Solution:
Molecules come closer and move slower.
Explanation:
During freezing (liquid to solid), energy is removed. The molecules of lose energy, slow down, and settle into a fixed, closely packed arrangement.