Key term
Edexcel GCSE Chemistry 1CH0
Key Concepts in Chemistry
Topic overviewFormulae, word equations and balanced equationsHazard symbols and assessing riskThe changing model of the atomProtons, neutrons and electronsThe nucleus, mass number and atomic massElements and isotopesCalculating particle numbers and relative atomic massMendeleev's periodic tableHow the modern periodic table is arrangedElectronic configuration and the periodic tableHow ionic bonds formIons in ionic compoundsFormulae of ionic compounds and ionic equationsNaming compounds and the ionic latticeCovalent bonds and moleculesDot and cross diagrams for simple moleculesClassifying substances and the properties of ionic compoundsProperties of simple molecular substances, and forms of carbonGraphite and diamondFullerenes and graphenePolymers and models of bondingThe properties of metalsRelative formula mass and percentage compositionEmpirical and molecular formulaeConservation of mass in closed and open systemsReacting masses from balanced equationsConcentration in grams per cubic decimetreMoles and the Avogadro constantLimiting reactants and stoichiometry
States of Matter and Mixtures
Topic overviewThe three states of matter and changes of stateEnergy changes during changes of state, and predicting statePure substances and melting point dataChoosing a separation techniqueSeparating a mixture in practicePaper chromatography and interpreting a chromatogramInvestigating inks by distillation and chromatographyMaking water potable
Chemical Changes
Topic overviewAcids, alkalis and the pH scaleIndicators: litmus, methyl orange and phenolphthaleinHydrogen ion concentration and the pH scaleInvestigating pH change when neutralising an acidDilute and concentrated, weak and strong acidsBases and alkalisReactions of acids, and testing for hydrogen and carbon dioxideNeutralisation and its ionic equationPreparing soluble salts from insoluble and soluble reactantsPreparing pure, dry copper sulfate crystalsCarrying out an acid-alkali titrationSolubility rulesPredicting precipitates and preparing an insoluble saltElectrolytes and what electrolysis isMovement of ions and predicting the products of molten electrolysisElectrolysis with inert electrodesWriting half equationsOxidation and reduction at the electrodesElectrolysis of copper sulfate solutionInvestigating the electrolysis of copper sulfate
Extracting Metals and Equilibria
Topic overviewInvestigating the reactivity of metalsDisplacement reactions as redox reactionsThe reactivity seriesOres, oxidation and reductionChoosing a method to extract a metalBiological methods of metal extractionCorrosion resistance and recycling metalsLife cycle assessmentReversible reactions and dynamic equilibriumThe Haber process and its conditionsChanging the position of an equilibrium
Transition Metals, Quantitative Chemistry and Industrial Processes
Topic overviewTransition metals and their propertiesCorrosion and electroplatingPreventing rustingAlloys and alloy steelsHow the uses of metals relate to their propertiesConcentration in mol dm-3 and titration calculationsCarrying out an accurate titrationPercentage yieldAtom economy and choosing a reaction pathwayMolar volume of a gasAvogadro's law and gas volumesThe Haber processConditions used in industrial reactionsFertilisers and ammonium saltsPreparing ammonium sulfate in the lab and in industryChemical cells and fuel cellsEvaluating fuel cells
Groups in the Periodic Table
Topic overviewThe groups of the periodic table, and the alkali metalsReactions of the alkali metals with waterThe pattern in alkali metal reactivity and why it happensPhysical properties of the halogensThe test for chlorine, and halogens reacting with metalsHydrogen halides, and explaining halogen reactivityDisplacement reactions of the halogensGroup 0: the noble gases
Rates of Reaction and Energy Changes
Topic overviewInvestigating the rate of a reactionMeasuring rate and interpreting rate graphsCollision theory and factors affecting rateCatalysts and enzymesExothermic and endothermic changesBond breaking, bond making and the overall energy changeBond energies, activation energy and reaction profiles
Fuels and Earth Science
Topic overviewHydrocarbons and crude oilFractional distillation and the fractionsProperties of the fractions and homologous seriesComplete and incomplete combustionCarbon monoxide and sootPollutants and acid rainHydrogen and fossil fuels comparedCracking and why it is necessaryThe Earth's early atmosphereHow the oceans formed and how oxygen appearedThe test for oxygen and the greenhouse gasesToday's atmosphere and evidence for climate change
Chemical Analysis, Organic Chemistry and Materials
Topic overviewWhy an ion test must be unique, and flame testsTests for metal ions and for ammoniaTests for carbonate, sulfate and halide ionsIdentifying the ions in an unknown saltInstrumental methods and flame photometryAlkanes and why they are saturatedAlkenes and why they are unsaturatedReactions of alkenes, and combustionWhat a polymer is, and how poly(ethene) formsOther addition polymers, and monomers from polymersUses of polymers, and natural polymers including DNAPolyesters and condensation polymerisationProblems with polymers and recyclingAlcohols and the -OH functional groupComparing the energy released by alcohol fuelsMaking ethanol by fermentation and distillationCarboxylic acids and the -COOH functional groupOxidising alcohols to carboxylic acids, and homologous seriesThe size of nanoparticlesUses and risks of nanoparticlesChoosing a material for a use
Key Concepts in Chemistry
How the modern periodic table is arranged
- 2 things to know
- Papers 1 and 2
Overview
How atomic number fixes an element's place in the table, periods and groups and why elements in a group behave alike, where the metals, non-metals and transition metals sit, and the metal and non-metal divide explained in terms of electrons.
What you need to know
Answer each one before you reveal it.
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Key term
Why does every element have a different atomic number?
Questions from this subtopic
Each one with the model answer underneath.
- 1
What does the atomic number of an element tell you about its atoms?
Model answer
It gives the number of protons in the nucleus of each atom.
- 2
How does atomic number fix an element's position in the periodic table?
Model answer
The elements are listed in order of increasing atomic number, so the number decides where the element sits.
- 3
An element sits immediately after carbon in the periodic table. What is its atomic number?
Model answer
Its atomic number is 7, one more than carbon's.
- 4
Why does every element have a different atomic number?
Model answer
Every element has its own unique number of protons.
- 5
What is a period in the periodic table?
Model answer
A period is a horizontal row of elements.
- 6
What is a group in the periodic table?
Model answer
A group is a vertical column of elements.
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