science quiz 1 sem 2

• properties of metal =

  -strong

  -brittle

  -good conductors of heat

  -has a high boiling point

  -has a low boiling point

  -malleable

  -sonorous

  -ductile
• properties of non-metal=

  -dull

  -has a low boiling point

  -has a low melting point

  -insulators

  -non-magnetic
• alloys are mixtures of different metals and melting them together
• alloys are atoms that are mixed together but not bonded together
• alloy examples =

  -coins

  -jewellery

  -aeroplanes

  -artificial joints
• litmus turns red in acid
• litmus turns blue in alkalis
• litmus turns purple in neutral
• the pH level of acid is 1-6
• the pH level of neutral is 7
• the pH level of alkalis is 8-12
• to vibrate means to move backwards and forwards very quickly
• sound travelling from a vibrating object to our ears is called sound wave
• everytime the object vibrates forward, the air in front of the object gets pushed forward
• the speed of sound waves in air is about 343 meters per sound
• when the particles in front of the object vibrate, those particles make other particles in front of them vibrate
• sound waves transfer sound energy
• the particles in the air are made to vibrate backwards and forwards in time with the vibrating objects
• sound also travels in liquid
• the substance that the sound waves moves through is called the medium
• waves can be reflected from surfaces
• the reflection of a sound wave is called an echo