Alkali Metals

• What is the group number of alkali metals in the Periodic Table?

  Group 1
• What is a characteristic property of alkali metals when they react with water?

  They react vigorously with water
• What are the learning objectives regarding alkali metals?

  • Understand similarities in reactions with water
  • Understand differences in reactions with air and water
  • Predict properties of other alkali metals
• Which element is at the bottom of Group 1 and is radioactive?

  Francium
• How is francium produced in nature?

  It is produced during the radioactive decay of uranium-235
• How much francium is estimated to be present in the Earth's crust?

  About 20-30g
• Why has no one ever seen a piece of francium?

  Because it is extremely short-lived
• What are the physical properties of the alkali metals listed in the study material?

  • Lithium (Li): Melting point 181 °C, Boiling point 1342 °C, Density 0.53 g cm⁻³
  • Sodium (Na): Melting point 98 °C, Boiling point 883 °C, Density 0.97 g cm⁻³
  • Potassium (K): Melting point 63 °C, Boiling point 760 °C, Density 0.86 g cm⁻³
  • Rubidium (Rb): Melting point 39 °C, Boiling point 686 °C, Density 1.53 g cm⁻³
  • Cesium (Cs): Melting point 29 °C, Boiling point 660 °C, Density 1.88 g cm⁻³
• What is the melting point of potassium (K)?

  63 °C
• What is the boiling point of sodium (Na)?

  883 °C
• What is the density of cesium (Cs)?

  1. 88 g cm⁻³
• What is the boiling point of rubidium (Rb)?

  686 °C
• What is the density of lithium (Li)?

  0.53 g cm⁻³
• What is the melting point of cesium (Cs)?

  29 °C
• What is the boiling point of potassium (K)?

  760 °C
• What is the density of sodium (Na)?

  0.97 g cm⁻³
• What is the melting point of rubidium (Rb)?

  39 °C
• What is the boiling point of cesium (Cs)?

  660 °C
• How can knowledge of trends in Group 1 help predict properties of other alkali metals?

  It allows predictions based on similarities and differences in reactivity