AQA AS Physical Chemistry 2024 exam questions with 100% correct answers

Who described atoms as solid spheres that make up different elements and when? - ANSWERS John Dalton in the 19th century Who suggested that atoms of a particular element had the same mass and atoms of different elements had different masses and when? - ANSWERS John Dalton in 1803 Who discovered the electron and when? - ANSWERS JJ Thomson, 1897 discovered electrons proving atoms weren't indivisible or solid. New model named plum pudding model Describe the plum pudding model - ANSWERS A ball of positive charge with negative electrons in embedded in it Who disproved the plum pudding model and how? - ANSWERS Rutherford and Geiger + Marsden By conducting the gold foil experiment. Positively charged alpha particles were fired at a very thin sheet of gold foil. If the plum pudding model was correct then the charged particles would have mostly deflected off the gold foil, but most of the particles passed straight through. Who discovered radioactivity and when? What did this show? - ANSWERS Henri Bequerel in 1896. Particles could come from inside the atom. State the three subatomic particles and name were they are found. - ANSWERS Protons - in the nucleus Neutrons - in the nucleus Electrons - in orbitals around the nucleus What is the (relative) charge and the (relative) mass of protons? - ANSWERS Charge: +1.062 x 10^-19 Relative charge: +1 Mass: 1.673 x 10^-27 kg Relative mass: 1 What is the (relative) charge and the (relative) mass of neutrons? - ANSWERS Charge: 0 Relative charge: 0 Mass: 1.675 x 10^-27 kg Relative mass: 1 What is the (relative) charge and the (relative) mass of electrons? - ANSWERS Charge: -1.062 x 10^-19 Relative charge: -1 Mass: 0.911 x 10^-30 kg Relative mass: 1/1840