Six Chemistry challenges

GCSE Chemistry

Both answers say the alloy is harder. Only one explains what stops the layers sliding.

3 marks

A bicycle frame is made from an aluminium alloy instead of pure aluminium. Explain why the alloy is harder.

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More Chemistry challenges

3 marks

Curriculum

Why does a higher temperature speed up a reaction?

Can you keep the mole ratio the right way round?

What does a constant mass prove?

What actually holds an ionic compound together?

Can you track ions to the right electrode?

Why does an exothermic mixture get warmer?

Can you trust the flame colour?

Which way does higher pressure move equilibrium?

Can one “green” feature settle a life-cycle comparison?

Why is brass harder than pure copper?

Why does a pure metal bend more easily?

Why does a concentrated solution react faster?

Why do compressed gases react faster?

Can you turn a mole ratio into product mass?

Which coefficient controls the product mass?

How do you measure dissolved solids in water?

How can two water samples be compared fairly?

What actually holds sodium chloride together?

Why do magnesium and oxygen form charged ions?

Can you route ions to the correct electrodes?

Can you balance electrode half equations?

What does a warmer neutralisation mixture show?

Why does an instant cold pack get colder?

Which ion gives a crimson flame?

Can one flame colour hide another ion?

Which side does higher pressure favour?

What if both equilibrium sides have equal gas totals?

When does a reusable bottle have lower impact?

Does refurbishing always settle a life-cycle choice?

Which atom does the subscript count?

Have the salt crystals actually been recovered?

How oversized is the model nucleus?

Which divisor makes the isotope average valid?

Is the electron total enough to fill the shells?

What makes two elements group partners?

Which clues classify the mystery element?

Have you counted both atoms in Cl₂?

Which metal survives heat and hammering?

Do different colours prove different ion charges?

Are correct formulas enough to balance an equation?

Which force completes an ionic bond?

Why do ions stay locked through a crystal?

Are methane’s electrons transferred or shared?

Which model truly represents a metal?

Does crossing a melting point make a gas?

Which state symbols complete this metal reaction?

Which forces yield when a molecular liquid boils?

What blocks the layers inside a harder alloy?

Which charge carrier moves through a metal strip?

Does using less nanoparticle coating settle the decision?

Where did the flask's measured mass go?

Which way round should the mass ratio go?

When do mole amounts become whole-number coefficients?

Which reactant actually runs out first?

Does concentration already give the solute mass?

Can a yield calculation pass 100%?

Have all reactants reached the atom-economy denominator?

Can no reaction put a metal at the top?

Does an electron on the right mean a gain?

Where does each half of a salt name come from?

Is every pH above zero alkaline?

Does equal concentration mean equal acid strength?

Which element forms at molten calcium iodide's positive electrode?

Will sulfate make sulfur at the anode?

Which oxygen change happens inside the kiln?

Which interval gives the activation energy?

Should three cell voltages be added or divided?

Which power system meets both depot limits?

Does a shorter reaction time mean a slower rate?

Does a catalyst supply the missing energy?

How can changing conditions reveal a reverse reaction?

Can you follow a piston change to the favoured side?

Does cooling favour an endothermic product?

Why can compression leave an equilibrium mixture unchanged?

Can a carbon-and-hydrogen compound fail the alkane test?

Which bond marks an addition-polymer monomer?

Where does the amino-acid account first fail?

Does a melting interval prove purity?

How much solvent belongs in the paint?

Can you verify a suspected hydrogen sample?