Chemistry

• The number of atoms in the outer shell of an element is the group number it is in
• The number of shells in an element tell you the period it is in
• When treating the water supply, sedimentation is used, this is the removal of large solid particles
• When treating the water supply, filtration is used, this is the removal of small solid particles
• When treating the water supply, chlorination is used, this is adding chlorine and levelling the ph
• When lithium is added to water it floats and fizzes
• When sodium is added to water it floats, fizzes and melts
• When potassium is added to water it floats, fizzes, melts and burns a lilac flame
• As you go down group 1 it becomes more reactive
• When flame tested lithium becomes crimson red
• When flame tested sodium becomes orange
• When flame tested potassium becomes lilac
• When flame tested calcium becomes brick red
• When flame tested barium becomes apple green
• When silver nitrate is added to chlorine it becomes a white precipitate
• When silver nitrate is added to bromide it turns a cream precipitate
• When sliver nitrate is added to iodide it turns to a yellow precipitate
• You test for hydrogen using the squeaky pop test, you insert a lit splint and it will make a squeaky pop
• Oxygen is present if it relights a glowing splint
• You test for carbon dioxide using the limewater test, which turns from colourless to cloudy
• An element contains only one type of atom
• A compound is a substance made up of two or more different elements chemically combined.
• Rates of reaction can be measured by change in mass, volume of gas formed, formation of precipitate
• Increasing the temperature make the particles move faster
• Breaking a solid into smaller pieces increases the surface area
• Adding a catalyst to the reaction lowers the activation energy of the reaction