6.2.2 Trends in Reactivity

• What are halogens classified as?

  Non-metals
• What type of ions do halogens form when they gain an electron?

  -1 ions
• What is the physical state of halogens at room temperature?

  Diatomic molecules
• In which column of the periodic table are halogens found?

  Column 7
• What are the main halogens and their states at room temperature?

  • Fluorine (F): pale yellow gas
  • Chlorine (Cl): greenish-yellow gas
  • Bromine (Br): dark red liquid
  • Iodine (I): shiny purple solid
• What does the acronym "FCIBR" stand for?

  • F: Decreasing
  • C: Reactivity
  • I: Br
• Why are halogens considered highly reactive?

  They readily gain electrons to form ions
• Why is reactivity decreasing in the image?

  The image suggests that reactivity is decreasing from left to right, likely referring to the decreasing reactivity of the halogens (F, Cl, Br, I) as you move down the periodic table.
• How could the decreasing reactivity of the halogens be useful in chemistry?

  • Allows for more controlled reactions
  • Enables the safe handling of less reactive halogens
  • Provides a way to selectively react with different halogens
• What is the order of decreasing reactivity for the halogens?

  F > Cl > Br > I
• How does the bond strength of the halogens compare, and how does this relate to their reactivity?

  The bond strength decreases from F to I, with F forming the strongest bonds and I forming the weakest, corresponding to their decreasing reactivity
• What are some key differences between the reactivity of fluorine (F) and iodine (I)?

  • Fluorine is the most reactive halogen, while iodine is the least reactive
  • Fluorine forms the strongest bonds, while iodine forms the weakest bonds
  • Fluorine is a highly oxidizing gas, while iodine is a solid at room temperature
• Why does halogen reactivity decrease down Group 7?

  Due to increasing atomic size
• Why does the reactivity of the halogens decrease as you go down the periodic table?

  The atomic radius increases, leading to weaker intermolecular forces and less reactivity
• What is the relationship between atomic size and electron gain in halogens?

  As atomic size increases, gaining electrons becomes harder
• How does atomic size affect electron gain in halogens?

  Larger atoms have outer electrons further from nucleus
• If you wanted to selectively react with bromine (Br) without reacting with iodine (I), which halogen would you choose to use?

  Chlorine (Cl)
• What happens to halogen reactivity down Group 7?

  Reactivity decreases down Group 7
• What ion does fluorine form when it gains an electron?

  -1 ion
• What is the most reactive halogen in Group 7?

  Fluorine (F)
• Why is fluorine the most reactive halogen?

  Its electrons are closest to the nucleus
• What is the trend of halogen reactivity from top to bottom of Group 7?

  • Fluorine (F) is most reactive
  • Astatine (At) is least reactive
• Which halogen is least reactive?

  Astatine (At)
• What is the reaction equation for fluorine and hydrogen?

  2H₂(g) + F₂(g) → 2HF(g)
• Why is fluorine considered highly reactive?

  It has the highest electronegativity
• What does the reaction between fluorine and hydrogen demonstrate?

  Fluorine reacts violently, releasing energy
• What can be inferred about the amount of fluorine needed for a violent reaction with hydrogen?

  A small amount can cause a violent reaction
• How does fluorine react with other substances?

  Very vigorously and explosively
• How do the physical states of halogens vary at room temperature?

  They range from gas to liquid to solid
• What is the physical state of bromine (Br) at room temperature?

  Dark red diatomic liquid
• What is the reactivity ranking of chlorine among halogens?

  Second most reactive after fluorine
• What is the significance of the energy released in the reaction between fluorine and hydrogen?

  It indicates the high reactivity of fluorine
• What is bromine's position among halogens in terms of reactivity?

  Third most reactive halogen
• How does the rate of bromine's reaction with hydrogen compare to chlorine's reaction with hydrogen?

  Bromine reacts at a moderate rate
• How does bromine's electronegativity compare to chlorine?

  Bromine has lower electronegativity than chlorine
• What is the chemical reaction when chlorine reacts with hydrogen?

  H₂(g) + Cl₂(g) → 2HCl(g)
• How does chlorine's reactivity compare to fluorine's?

  Chlorine's reactions are less explosive
• What factors contribute to bromine's reduced reactivity compared to chlorine and fluorine?

  Its larger atomic size and further electrons
• What is the chemical reaction when bromine reacts with hydrogen?

  H₂(g) + Br₂(g) → 2HBr(g)
• What is the energy change during the reaction of bromine with hydrogen?

  The reaction releases energy