Chemistry (Periodic Table)

• Arrangement of Elements

  • The Periodic table is a method of classifying elements.
  • Elements are arranged in order of increasing atomic number (each proceeding element has one more proton)
  • Made up of rows called periods and columns called groups, the position of an element helps determine its electronic configuration.
  • Period number: number of electron shells
  • Group number: number of outer shell electrons

  Elements in the same group have similar chemical properties.
• Periodic Trends

  1. The table moves from metals on the left to non-metals on the right.
  2. Down a group of metals, elements become more reactive.
  3. With non-metals going down a group, reactivity decreases.
• • Group 1 metals/ Alkali metals: Lithium, Sodium and Potassium
• Chemical Properties of group 1 Metals include:

  1. Readily react with oxygen and water; stored in oil
  2. React violently with chlorine
  3. Burst into flames when heated with oxygen[red flame for lithium; yellow flame for sodium; lilac flame for potassium]
  4. Produce soluble white compounds
  5. React with water to form alkaline metal and hydrogen gas
• Physical Properties of group 1 Metals include:

  1. Good conductors of heat and electricity
  2. Soft and easy to cut
  3. Shiny when freshly cut
  4. Melting points decrease down the group.
  5. Increase density down the group
• Group 1 Metal Reactions with Water

  • Alkali Metals react vigorously with water and hydrogen is given off as leaving an alkaline solution.
• Group 1 Metal Reactions with Chlorine

  • If you heat the metals and plunge them into a glass jar of Chlorine, they burst into flames and burn brightly forming a Chloride.
• Group 1 Metal Reactions with Oxygen

  • The heated metals also burst into flames when put in a jar of oxygen to make oxides.
• Group 7 metals/ Halogens (Diatomic Molecules)- Fluorine, Chlorine, Bromine and Iodine.
• Chemical Properties of Group 7 non-metals include:

  1. Halogens lose reactivity down the group
  2. They are diatomic
• Physical Properties of Group 7 non-metals include:

  1. Poor conductors of heat and electricity
  2. Are dull and brittle in solid state
  3. They have low melting and boiling point
• Physical Properties of Transition Elements:

  • High melting & boiling points
  • Malleable and ductile
  • Good conductors of heat & electricity
  • High density
• Chemical Properties of Transition Elements:

  • Act as catalysts
  • Form coloured compounds
  • Variable Oxidation Numbers (Iron (II) or Iron (III) )