Atoms, Elements and Compounds

Worked examples (12)extended set

• 1Classifying particle diagrams
• 2Describing elements, compounds and mixtures
• 3Element, compound or mixture? (multiple choice)
• 4Why carbon dioxide is a compound (multiple choice)
• 5Choosing substances from a list
• 6A mixture of hydrogen and chlorine or hydrogen chloride?
• 7Fixed composition: reducing copper(II) oxide
• 8Separating salt, sand and iron filings
• 9Air is a mixture
• 10Recognising an alloy from a structure diagram
• 11Counting elements and atoms in formulae
• 12Showing that water is a compound by electrolysis

Model answers (6)

• ✓Model answer — Paper 2 multiple-choice style
• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style

Worked examples (12)extended set

• 1Labelling an atom and its particles
• 2Electronic configurations of atoms and ions
• 3Comparing a potassium ion and a chloride ion (multiple choice)
• 4Protons, neutrons and electrons in atoms and ions
• 5Identifying ions from their particles
• 6Shells, outer electrons and position in the Periodic Table
• 7One more neutron than electrons (multiple choice)
• 8Counting electrons in a molecule and an ion
• 9Identifying particles from shell diagrams
• 10Atoms and ions with the same electronic configuration
• 11Two ions with 18 electrons
• 12True or false? Statements about atoms

Model answers (6)

• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style

Worked examples (12)extended set

• 1Picking out isotopes from nuclide symbols
• 2Protons, neutrons and electrons in atoms and ions
• 3Why isotopes react in the same way (multiple choice)
• 4Relative atomic mass of gallium from percentage abundances
• 5Relative atomic mass from an abundance ratio
• 6Relative atomic mass of neon from a bar chart of three isotopes
• 7Whole-number relative atomic masses and the carbon-12 standard
• 8Comparing two isotopic samples of calcium in the laboratory
• 9Finding a percentage abundance quickly (multiple choice)
• 10Working backwards from relative atomic mass to abundance
• 11Sorting atoms, isotopes and ions from particle counts
• 12Finding the mass of an unknown isotope of silver

Model answers (6)

• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — 0620/42-style structured question
• ✓Model answer — 0620/42-style structured question

Worked examples (12)extended set

• 1How potassium and fluorine atoms become ions
• 2Defining the ionic bond and drawing the ions in lithium fluoride
• 3Correcting a student's dot-and-cross diagram for calcium fluoride
• 4Electron transfer in calcium nitride (multiple choice)
• 5Formula from positions in the Periodic Table (multiple choice)
• 6Ions with noble gas electronic configurations
• 7Completing and describing the lattice of magnesium oxide
• 8Testing the conductivity of zinc chloride as it melts
• 9Telling an ionic compound from a metal
• 10Using data to pick out an ionic compound and explain its melting point
• 11Working backwards from a dot-and-cross diagram of an unknown compound
• 12Identifying an ionic compound from its ions

Model answers (6)

• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style

Worked examples (12)extended set

• 1Defining a covalent bond and counting the bonds in a molecule
• 2Choosing the correct dot-and-cross diagram for water (multiple choice)
• 3Correcting a dot-and-cross diagram for carbon dioxide
• 4Completing the dot-and-cross diagram for ethene
• 5Dot-and-cross description for hydrogen peroxide
• 6Spotting a simple molecular substance from data (multiple choice)
• 7Why methane boils easily but is hard to break down
• 8Testing whether liquids conduct
• 9Choosing molecules from a list by their bonds and atoms
• 10Strong bonds in four different structures
• 11Dot-and-cross diagram for hydrogen cyanide
• 12Methanal: a double bond, lone pairs and a low boiling point

Model answers (6)

• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) data-trend style

Worked examples (12)extended set

• 1Recognising diamond and graphite from their structures
• 2Linking the uses of diamond and graphite to their structures
• 3The structure of silicon(IV) oxide (multiple choice)
• 4Identifying the atoms in part of a silicon(IV) oxide lattice
• 5Why diamond and silicon(IV) oxide behave alike
• 6Testing solids for electrical conductivity
• 7Choosing substances by structure from a list
• 8Comparing graphite and diamond (multiple choice)
• 9Predicting the properties of silicon carbide
• 10Graphite's layers: bonds within and forces between
• 11Carbon dioxide and silicon(IV) oxide: same group, different structures
• 12Counting covalent bonds in giant structures using moles

Model answers (6)

• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style

Worked examples (12)extended set

• 1Naming the particles in a metal lattice
• 2Which statement describes metallic bonding? (multiple choice)
• 3Describing metallic bonding for three marks
• 4Why silver conducts but silver chloride does not
• 5Malleability and ductility from a layer diagram
• 6A metal or an ionic compound? (multiple choice)
• 7Completing a bonding table for four substances
• 8Testing solids for electrical conductivity
• 9Why an alloy is harder (multiple choice)
• 10A liquid metal and a liquid non-metal
• 11Correcting a flawed description of metallic bonding
• 12Identifying the metal from a table of properties

Model answers (6)

• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 short-answer style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 structured style
• ✓Model answer — Paper 4 (Extended) structured style
• ✓Model answer — Paper 4 (Extended) structured style