7697408
Descrição
FlashCards por Bella Evershed, atualizado more than 1 year ago
|
Criado por Bella Evershed
quase 8 anos atrás
|
|
| Questão | Responda |
| How was the plum pudding model in 1897 seen to have looked? | Electrons were seen to have been randomly distributed in a sphere of positive charge. |
| How was the alpha scattering experiment done? | Ernest Rutherford, Hans Geiger and Ernest Marsden investigated the scattering of alpha particles by sending them through a thin piece of foil (gold). |
| How was the alpha scattering experiment measured? | They measured the number of aparticles deflected per second at different angles. |
| What results of the Alpha scattering experiment show? | The results showed that most of the alpha particles passed straight through, however some bounced back. The number of alpha particles deflected per minute decreased as the angle of deflection increased. About 1 in 1000 alpha particles deflected per minute were deflected by more than 90 degrees. |
| What did the alpha scattering experiment prove? | It proved that the must be something more dense in an atom, which is a nucleus. |
| What did they deduct about the nucleus? | It’s positively charged because most alpha particles are repelled. The nucleus is much smaller than the atom because most alpha particles passed through without deflection.(the nucleus in diameter is 100,000 times smaller than the atom) It’s where most of the mass of the atom is located. |
| What are the 2 main types of radiation? | Infrared radiation (with heat) Ionising radiation. |
| What is Ionising radiation? | When an alpha particle zooms past a negatively charged electron, It gets attracted and rips off the electron from the atom. However the electron doesn’t join the alpha partical because it moves to quickly. The atom then becomes charged because the total amount of positive particles no longer equal the amount of negative particles so the charge is unbalanced. We now call the atom an ion. |
| What is an isotope? | When an element has the same number of protons but a different number of neutrons |
| What kind of radiation is the most ionising? | Alpha radiation |
| What can beta penetrate? | Air and paper |
| What can beta be stopped by? | A thin piece of aluminium |
| What can gama penetrate? | Air, paper, thin metal |
| What can gama be stopped by? | Concrete or lead |
| What can alpha penetrate | Least penetrating, air |
| What can alpha be stopped by | absorbed by a hand |
| Which type of radiation is the most penetrating | Gama |
| Why are Beta and Alpha particles deflected by electric fields, but gamma is not? | Because Alpha particles are positively charge, therefore will attract to the negatively charged plate. Beta is negatively charged so will attract to the positively charged plate. Gama is neutral so is not deflected |
| What happens when alpha and beta radiation are deflected in a magnetic field? | They experice a deflecting force provided their motion is not parallel to the field |
| If a star is 30X the mass of our sun, what will it end up as? | A black hole |
| What’s the life cycle of a star which includes our sun? | 1) protostar 2)Main sequence star 3)red giant 4)white dwarf 5)black dwarf |
| What’s the life cycle of a star which includes our sun? | 1) protostar 2) main sequence star 3)red super giant 4) super nova 5)black hole 5)neutron star |
| What do the control rods in nuclear fission do? | Absorb extra neutrons to keep the chain reaction stable |
| How does nuclear fission take place | A neutron is absorbed by a nucleus (uranium). The atom becomes unstable and splits in two. It releases lot’s of energy and 2-3 electrons. The energy is used to heat up water or gass. The water turns to steam, it drives the turbine and generator to make electricity. |
| What is acceleration? | The change of velocity per second (v=u+at) |
| What is deaccelerationn | slowing down |
| What is the limit of proportionality? | When a spring is perminently damaged and will not go back to it's original length |
| Define thinking distance | The distance travelled in the time taken to react |
| Define breaking distance | The distance travelled while breaks are being applied |
| Define stopping distance? | Theo outcome of both thinking distance and stopping distance |
| What affects thinking distance? | Alcohol and other drugs, being distracted (phone talking to someone) tiredness |
| What affects braking distance? | Road conditions Car conditions (breaks tyres) speed |
| What are the forces opposing driving force? | Air resistence Friction Breaking force |
| What is conservation of momentum? | In a closed system the total momentum before equals the total momentum after |
| What is momentum? | Property of a moving object |
| What is the product of mass and velocity? | Momentum |
Quer criar seus próprios Flashcards gratuitos com GoConqr? Saiba mais.