Chapter: 07. Forms Of Matter Solids, Liquids And Gases
Section A: Multiple Choice Questions
Section B: Fill in the Blanks
Section C: True or False
Section D: Short Answer Questions
Matter is anything that has mass and occupies space. Liquids do not have a fixed shape but take the shape of their container, and they flow easily. Examples of solids include a table, chair, mobile phone, or a pen. (Any two valid examples from the chapter are acceptable) A liquid fills the bottom part of a container and takes its shape, maintaining a fixed volume. A gas, however, spreads out to fill the entire space of any container it is in, and does not have a fixed volume or shape. Drinking plenty of water every day is important because many plants and animals live in water, and it is essential for our health. Section E: Diagram-Based Question
Question 1
Beaker 1 shows a solid. Beaker 2 shows a liquid. Beaker 3 shows a gas. The particles in beaker 3 (gas) are shown spread out everywhere because gases do not have a fixed shape or size and will expand to fill the entire space of the container they are in. The contents of Beaker 2 (liquid) and Beaker 3 (gas) would change shape if poured into a different shaped container. The solid in Beaker 1 would keep its fixed shape. Section F: Long Answer Questions
Solids have a fixed shape and a fixed size; their particles are tightly packed, so they cannot flow. Liquids have a fixed volume but no fixed shape, taking the shape of their container, and they flow easily because their particles can move past one another. Gases have neither a fixed shape nor a fixed volume, expanding to fill the entire space of any container, and they flow easily because their particles are far apart and move freely. In the balloon experiment, two inflated balloons of equal size were tied to a stick, balancing it. When one balloon was pricked, the stick tilted towards the side of the unpricked, inflated balloon. This tells us that air, even though we cannot see it, has mass. The air inside the inflated balloon contributed to its weight, and when that air escaped, the side of the stick became lighter, proving that air is a form of matter that occupies space and has mass. 
Answer key