Iodine is most commonly used in science to test the presence of starch in food. In water, it is an orangish\brown colour but if you put it on a food that contains starch it will turn a darkblue\black colour. For example, if you put it on bread, it will turn darkblue\black.

Gases, Liquids and Solids

• Gases, liquids and solids are al made up of atoms, molecules and/or ions, but the behaviours of these particles differ in the three phases

Particles in a:

• Gas are well separated with no regular arrangement
  • gas vibrate and move freely at high speeds
• Liquid are close together with no regular arrangement
  • liquid vibrate, move about, and slide past each other
• Solid are tightly packed, usually in a regular pattern
  • solid vibrate (jiggle) but generally do not move from place to place

Liquids and solids are often referred to as condensed phases because the particles are very... (More)