group 1 alkali metals

• Which element is in group 1, period 2?

  Lithium
• How do you work out the number of electrons an element has?

  By using its atomic number
• Which number tells you the total number of particles in the nucleus?

  Mass number
• Which two particles are found in the nucleus?

  Protons and neutrons
• What is the relative mass of a neutron?

  1 atomic mass unit
• Draw the electron arrangement for sodium.

  2, 8, 1
• What are the three common reactions of alkali metals?

  • Alkali Metal + Oxygen → Metal Oxide
  • Alkali Metal + Water → Hydrogen + Metal Hydroxide
  • Alkali Metal + Chlorine → Metal Chloride
• Write the word equation for lithium reacting with oxygen.

  Lithium + Oxygen → lithium oxide
• Write the word equation for sodium reacting with water.

  Sodium + Water → sodium hydroxide + hydrogen
• Write the word equation for potassium reacting with chlorine.

  Potassium + Chlorine → potassium chloride
• What is the hint for writing the symbol equation for lithium reacting with oxygen?

  Oxygen exists as O$_2$
• What is the hint for writing the symbol equation for sodium reacting with water?

  Hydrogen exists as H$_2$
• What is the hint for writing the symbol equation for potassium reacting with chlorine?

  Chlorine exists as Cl$_2$
• What happens to an alkali metal's outer electron during a reaction?

  • The outer electron is lost
  • Forms positively charged ions
  • Increases reactivity
• Why does reactivity increase down group 1 elements?

  Atoms become larger and outer electron is lost more easily
• What happens to the outer electron as you go down group 1?

  It becomes further from the nucleus
• What decreases as you go down group 1 elements?

  The force of attraction between nucleus and outer electron
• What is the challenge question regarding potassium and sodium's reactivity?

  Explain why potassium is more reactive than sodium
• Write the balanced symbol equation for potassium reacting with water.

  2K + 2H$_2$O → 2KOH + H$_2$
• Write the balanced symbol equation for sodium reacting with chlorine.

  2Na + Cl$_2$ → 2NaCl
• Write the balanced symbol equation for potassium reacting with oxygen.

  4K + O$_2$ → 2K$_2$O
• Write the balanced symbol equation for caesium reacting with fluorine.

  2Cs + F$_2$ → 2CsF