Area and Volume
4 Minutes
Area and volume for kids: learn the difference between 2D area and 3D volume, and how volume works in solids, liquids, and gases. An English science lesson.
- What 2D area and 3D volume mean using colored powder
- Compressing solids, liquids, and gases using a syringe
- Finding the volume of an irregular solid using water
What this lesson teaches
Area is the amount of space an object covers across a two-dimensional surface, while volume is the amount of three-dimensional space an object occupies or can hold inside it.
Difference between area and volume
Area measures how much space an object covers across a flat, two-dimensional surface, whether it is a circle, a rectangle, or an irregular shape. Volume measures how much space an object occupies in three dimensions, which is its capacity. For example, colored powder spread flat in a circle forms an area, but when that circle is given height to become a cylinder, the powder needed to fill it represents its volume. Similarly, when a water balloon bursts against a wall, the water spread across the wall is the area, while the amount of water held inside the balloon is the volume.
How states of matter hold volume
- Solids have a fixed shape and their volume cannot be easily compressed or changed by hitting or pressing because the gap between their molecules is very small.
- Liquids have no defined shape, take the shape of their container such as a cylinder or a sphere, and are measured in liters.
- Liquids cannot be compressed, which can be seen when pressing the plunger of a syringe filled with water while blocking the nozzle.
- Gases can be compressed easily inside a syringe with a closed opening because the gap between gas molecules is very large.
Measuring the volume of irregular solids
A solid with a regular form like a cube, cuboid, or cylinder has a defined shape that can be used to determine its volume. Some solids do not have a defined or regular shape. The volume of an irregular solid can be found by dropping it into a liquid such as water. The amount by which the water level rises in the container is equal to the volume of that solid.
Area and volume of planet Earth
The difference between two dimensions and three dimensions can be seen on planet Earth. The outer surface of the Earth covers an area of 510.1 million square kilometers. As a three-dimensional object, the space Earth occupies gives it a volume of 1.08 quadrillion cubic kilometers.