paper 1

• What are the components of an atom's structure?

  Nucleus and electrons
• How is mass number calculated?

  Mass number = Protons + Neutrons
• What defines isotopes?

  Same protons, different neutrons
• What is a compound?

  Chemically bonded elements
• What were the historical models of the atom?

  • Dalton: Solid spheres
  • Thomson: Plum pudding model
  • Rutherford: Nuclear model
  • Bohr: Electron shells
• Who created the periodic table and how did he organize it?

  Mendeleev ordered by atomic mass
• How is the modern periodic table organized?

  Ordered by atomic number
• What are groups in the periodic table?

  Columns with same outer electrons
• What are periods in the periodic table?

  Rows with same shells
• What characterizes Group 1 elements?

  Very reactive, 1 outer electron
• What happens when Group 1 elements react with water?

  Produces hydrogen and alkali
• What are the characteristics of Group 7 elements?

  Diatomic, form salts with metals
• How does reactivity change in Group 7 elements?

  Reactivity decreases down the group
• What defines Group 0 elements?

  Inert with full outer shell
• What are the types of bonding in chemistry?

  • Ionic Bonding: Metal + Non-metal, electrons transferred
  • Covalent Bonding: Non-metals share electrons
  • Metallic Bonding: Metal atoms share delocalised electrons
• What occurs during ionic bonding?

  Electrons are transferred to form charged ions
• What are the properties of ionic compounds?

  High melting/boiling points, conduct when molten
• How do non-metals bond covalently?

  By sharing electrons
• What are the properties of simple covalent molecules?

  Low melting/boiling points due to weak forces
• What are giant covalent structures?

  High melting points, e.g., diamond and graphite
• What is the structure of diamond?

  Hard, 4 bonds per atom
• How does graphite conduct electricity?

  Due to 3 bonds per atom and layers
• What is graphene?

  One-layer graphite, strong and conducts
• What are fullerenes?

  Hollow cages, e.g., nanotubes
• What are the states of matter and their transitions?

  • Solid → Liquid: Melting
  • Liquid → Gas: Boiling
  • Gas → Liquid: Condensation
  • Liquid → Solid: Freezing
• What is a nanoparticle?

  High surface area:volume ratio
• How are nanoparticles used?

  In medicine and sun cream
• What does conservation of mass state?

  Mass before = Mass after
• What happens if gas is lost during a reaction?

  Reaction occurs in an open container
• How is relative formula mass (Mr) calculated?

  Sum of atomic masses in formula
• What is the relationship between moles and grams?

  1 mol = Ar or Mr in grams
• How do you calculate moles?

  Moles = Mass ÷ Mr
• How is concentration calculated?

  1. (mol/dm³) = Moles ÷ Volume (dm³)
• How is percentage yield calculated?

  % Yield = (Actual ÷ Theoretical) × 100
• What does atom economy measure?

  Higher = Less waste, more sustainable
• What is the reactivity series of metals?

  Most to least reactive:

  • K, Na, Ca, Mg, Al, Zn, Fe, Cu, Ag, Au
• What does a more reactive metal do?

  Reacts faster with acid/water
• How are metals extracted above carbon?

  By electrolysis
• How are metals extracted below carbon?

  By reduction with carbon
• How is gold found in nature?

  Found unreacted