Group 1 Alkali Metals

• What are the group 1 elements known as?

  Alkali metals
• Which elements are included in the alkali metals group?

  Lithium, sodium, potassium, rubidium, cesium, and francium
• How do alkali metals differ from most other metals?

  They are relatively soft, have low densities, and low melting points
• What is the reactivity of alkali metals compared to other metals?

  They are much more reactive than other metals
• With which substances do alkali metals react vigorously?

  Water, oxygen, and group 7 elements such as chlorine
• What happens to the reactivity of alkali metals as you go down the group?

  The elements become more reactive
• Which alkali metal can ignite spontaneously at room temperature?

  Cesium
• What trend occurs in melting and boiling points as you go down the alkali metals group?

  Melting points and boiling points decrease
• Why doesn't sodium catch fire when sprinkled on potatoes?

  Because sodium is in a stable ionic compound in table salt
• Why are alkali metals so reactive?

  They have one electron in their outermost shell that they can easily lose
• What charge do alkali metals become when they lose their outer electron?

  They become a one positive ion
• How does the atomic radius affect the reactivity of alkali metals?

  As the atomic radius increases, the outermost electron is further from the nucleus, making it easier to lose
• What does the term reactivity refer to?

  How easily atoms can lose or gain electrons
• What type of compounds do alkali metals typically form with non-metals?

  Ionic compounds
• What happens when sodium reacts with chlorine?

  Sodium donates an electron to chlorine, forming sodium chloride
• What is the appearance of ionic compounds formed by alkali metals?

  They are generally white solids
• How do ionic compounds behave in water?

  They tend to dissolve in water and form colorless solutions
• What do alkali metals produce when they react with water?

  A metal hydroxide and hydrogen gas
• What is the reaction equation for sodium reacting with water?

  $\text{Sodium} +$$\text{Water} \rightarrow \text{Sodium Hydroxide} +$$\text{Hydrogen}$
• What happens to the energy released in reactions as you go down the alkali metals group?

  More energy is released, especially from potassium onwards
• What do alkali metals form when they react with chlorine gas?

  White metal chloride salts
• What is the reaction equation for sodium reacting with chlorine?

  $\text{Sodium} +$$\text{Chlorine} \rightarrow \text{Sodium Chloride}$
• What do alkali metals form when they react with oxygen?

  Metal oxides
• What is the reaction equation for lithium reacting with oxygen?

  $\text{Lithium} +$$\text{Oxygen} \rightarrow \text{Lithium Oxide} (Li_2O)$
• What can sodium and oxygen also react to form besides sodium oxide?

  Sodium peroxide
• What types of oxides can potassium form when reacting with oxygen?

  Potassium can form potassium peroxide or potassium superoxide
• What are the general properties and trends of alkali metals?

  • Soft with low densities and low melting points
  • More reactive than other metals
  • Reactivity increases down the group
  • Melting and boiling points decrease down the group
• What is the process of ionic compound formation in alkali metals?

  • Alkali metals lose one electron to become positive ions
  • They react with non-metals to form ionic compounds
  • Example: Sodium donates an electron to chlorine to form sodium chloride
• How do alkali metals react with water, chlorine, and oxygen?

  • React with water to produce metal hydroxide and hydrogen gas
  • React with chlorine to form white metal chloride salts
  • React with oxygen to form metal oxides
• What is the significance of the energy released in alkali metal reactions?

  • More energy is released as you go down the group
  • Potassium and below can ignite hydrogen gas produced in reactions
• What are the types of oxides formed by alkali metals when reacting with oxygen?

  • Lithium forms lithium oxide (Li2O)
  • Sodium forms sodium oxide (Na2O) and sodium peroxide (Na2O2)
  • Potassium forms potassium peroxide (K2O2) or potassium superoxide (KO2)