AQA GCSE Combined Science: Trilogy chemistry topics overview quiz quiz

Atoms of the same element with different numbers of protons

Atoms of two completely different elements that happen to share the same number of neutrons

Atoms of the same element with the same protons but different numbers of neutrons

Atoms that have lost or gained electrons

Because heating the solid salt up creates brand new free electrons inside it

Because solid salt has no ions

Because molten salt becomes a metal

Because the ions are free to move and carry charge only when molten

Avogadro's number, 6.02 times 10 to the power 23

1000 particles

100 particles

Exactly one million separate particles of the substance

Just a salt and hydrogen gas only

Salt, water and carbon dioxide

Salt and water only

Metal and oxygen

Products are higher in energy than reactants

Products and reactants have equal energy

Products are lower in energy than reactants

Energy levels cannot be compared

By raising the activation energy

By being used up to release energy

By permanently increasing the temperature of the reaction mixture itself

By providing an alternative pathway with a lower activation energy

C n H 2n+2

C n H 2n

C n H n

C n H 2n-2

A squeaky pop with a lit splint

Limewater turns milky (cloudy)

A glowing splint relights

Damp litmus paper is bleached white

It is about 78% oxygen and 21% nitrogen

It is mostly carbon dioxide as in the early atmosphere

It is about 78% nitrogen and 21% oxygen

It is half nitrogen and half carbon dioxide

Iron, because it is less reactive than carbon

Copper, because it is much less reactive than carbon is

Gold, because it is found uncombined

Aluminium, because it is more reactive than carbon