Gases like liquids have mass, conform to the shape of their container, and expand to fill the container. Understand that all matter has mass and takes up space, and that gases conform to the shape of their container and will expand to fill the container. Electric circuits require a power source, such as a battery, and a closed circuit to see a bulb light, a motor turn, or a dial move. The number and arrangement of batteries affects the brightness of a bulb or speed of a motor. Understand how the number and arrangement of batteries, and the different circuit configurations affect the brightness of a bulb or the speed of a motor.
Magnets attract and repel each other and attract certain kinds of other materials.
Recognize that magnets attract certain materials. Sound is produced by vibrating objects. The pitch of the sound is related to how quickly it vibrates. The loudness is related to the size of the vibration. Recognize which general categories of common materials are conductors and which are insulators.