C4.1 Flashcards
What are the three main groups in the periodic table that have predictable properties?
Group 1 (Alkali metals), Group 7 (Halogens), and Group 0 (Noble gases).
How does reactivity change as you go down Group 1?
Reactivity increases because the outer electron is further from the nucleus and easier to lose.
What happens when alkali metals (Group 1) react with water?
They produce an alkaline solution and hydrogen gas.
Example:
2Na + 2H₂O → 2NaOH + H₂ (Sodium hydroxide + Hydrogen)
Why do Group 1 elements have similar properties?
They all have one electron in their outer shell, making them highly reactive.
What are the trends in melting and boiling points in Group 1?
Melting and boiling points decrease as you go down the group.
How do boiling points change as you go down Group 0 (Noble Gases)?
Boiling points increase as relative atomic mass increases.
How do alkali metals react with oxygen?
They form metal oxides.
Example: 4Li + O₂ → 2Li₂O (Lithium oxide)
How do alkali metals react with chlorine?
They form white metal chloride salts.
Example: 2K + Cl₂ → 2KCl (Potassium chloride)
How do halogens react with metals?
They form ionic compounds (halide salts).
Example: 2Na + Cl₂ → 2NaCl (Sodium chloride)
Why are noble gases (Group 0) unreactive?
They have full outer electron shells, making them stable and unlikely to form bonds.
: What are common uses of noble gases?
Helium → Balloons & airships (low density, non-flammable).
Neon → Advertising signs (glows when electricity passes through).
Argon → Light bulbs (unreactive, prevents filament burning).
What are the key properties of Group 7 elements (Halogens)?
Diatomic molecules (exist as pairs of atoms: Cl₂, Br₂, I₂).
Highly reactive non-metals.
Form -1 ions when reacting with metals.
How does reactivity change as you go down Group 7?
Reactivity decreases because outer electrons are further from the nucleus, making it harder to attract electrons.
How do halogens react with non-metals?
They form covalent compounds (share electrons).
Example: H₂ + Cl₂ → 2HCl (Hydrogen chloride)
What happens in a displacement reaction between halogens?
A more reactive halogen will displace a less reactive halogen from a compound.
Example: Cl₂ + 2KBr → 2KCl + Br₂
(Chlorine displaces bromine because it is more reactive)
How can you predict an element’s reactivity based on the periodic table?
Left side (metals) → Tend to lose electrons and form positive ions.
Right side (non-metals) → Tend to gain electrons and form negative ions.
What happens to the melting and boiling points of halogens as you go down the group?
They increase because of stronger intermolecular forces.
What are the general properties of transition metals compared to Group 1 metals?
Harder and stronger than alkali metals.
Higher melting and boiling points.
Less reactive with oxygen and water.
Can form ions with different charges (e.g., Fe²⁺, Fe³⁺).
Form colored compounds.
Good catalysts.
How do metals react with acids?
Metal + Acid → Salt + Hydrogen
Example: Zn + 2HCl → ZnCl₂ + H₂
What determines how reactive a metal is?
Its ability to lose electrons and form positive ions. More reactive metals lose electrons more easily.
Why are transition metals useful in industry?
They act as catalysts and form strong, durable materials.
How do metals react with water?
Metal + Water → Metal Hydroxide + Hydrogen
Example: 2K + 2H₂O → 2KOH + H₂
How can we use experimental results to deduce a reactivity series of metals?
Most vigorous reactions = most reactive metals.
No reaction = least reactive metals.
What is the general order of metal reactivity (most to least reactive)?
Potassium > Sodium > Calcium > Magnesium > Zinc > Iron > Copper > Gold
(“Please Stop Calling Me A Zebra, I Constantly Get Hunted” - mnemonic!)
Why don’t very unreactive metals (e.g., gold and platinum) react with acids or water?
They do not easily form ions, making them very stable.
