all of paper 1 Flashcards
Energy is transformed from the CPV through the metal base of the cooling unit. Explain how the process occurs
When metal heated, delocalized electrons
gain kinetic energy and move quicker
transfer kinetic energy to other electrons
when they collide with them.
Stage 2 features that could help the metal cooling transfer energy quicker
Larger surface area black paint.
(black is a good emitter of IR radiation)
The speed of entry of the water is greater than, equal or less than when it leaves the water.
Same speed,
loss of gravitational potential, energy transfer to kinetic energy
Water moving turns the turbine to produce electricity. Describe the energy transfers taking place in the system.
Stored water has energy in its gravitational potential energy.
Energy transferred mechanically.
Transferred to the kinetic store of the water as it flows through the tunnel
Energy transferred to the kinetic store of the turbine as it turns.
why is stand by not good
uses electricity
generating electricity produces CO2
CO2 contributes to global warming
Describe how electricity is generated in a hydroelectric power station
-water moves from high to low level
-transferring GPE to KE
-rotating turbine to turn generator
-transferring KE to ELECTRICAL energy
shale gas
Low CO2 emissions
free - Only cost is the extraction.
Digging destroys habitats. Extracting shale gas involves digging underground- expensive. Extraction releases CO2.
Nuclear fission.
Reliable, no CO2 emissions, high energy density fuel, longer operating life
radioactive waste, accidents at nuclear stations , longer start up time, high building costs
Control roads and nuclear fission.
Chain reactions occur.
Neutrons are released, control rods absorb.
Neutrons can be moved up and down
to increase or decrease rate of chain reactions.
What would happen if the reaction were to continue?
Uncontrolled chain reaction.
Number of neutrons released increases exponentially.
nuclear explosion.
Nuclear power as an energy source.
Reliable produces no greenhouse gases.
Radioactive waste dangerous to dispose of.
A small amount of nuclear fuel generates a large amount of electricity.
How does the shape of the graph show the filament lamp is known on the conductor?
As potential difference increases, current increases.
the current increase decreases because
Temperature of the filament bulb increases as current increases. So resistance increases causing current to decrease.
2 improvements Measuring resistance of LDR.
wait time before each light intensity.
Digital Ammeter
underground cables
cannot be seen
not a hazard to aircrafts
not likely to be damaged
reduced shock hazard
Shape of the graph shows that the LDR is no normal conductor.
The graph is a curve, so not directly proportional.
Describe the difference between conventional current and electron flow
Electron current is the flow of electrons in a circuit.
Electrons have negative charge so they float towards positive terminal.
Conventional currents is the reversed movement of positive charge.
Moves towards the negative terminal.
On a current against potential difference graph
the smaller the gradient
the greater the resistance
Because Lower value for currents for all values of potential difference.
Benefit of connecting the heating elements in parallel.
Current will flow More
because the total resistance in circuit is lower.
More energy transferred.
Because potential difference is not shared between elements. As in series.
(elements can be turned on and off - because a switch can be placed on each branch.)
graph of Mean total resistance against the number of resistors in parallel. what does it tell you
As the number of resistors in parallel increases, the resistance decreases. The relationship is inversely proportional.
Explain how an object with no charge may become positively charged
Negative charged electrons.
electrons transferred
Away from the object.
explain why the students hair stands on end when the generator is switched on
Each head gained the same type of charge.
Same charge as repel.
Why does friction cause child to become charged?
Electron transfer from trampoline to child
Why does copper wire prevent shock?
Good conductor.
So low buildup of charge. ( or smaller potential difference.)
When the youth stops jumping, he touches the metal side of trampoline. Explain why he receives an electric shock.
There’s a potential difference between child on trampoline.
Electrons transfer from child to trampoline.
the charge is earthed
What can you tell about the charge on the child if the slide were made from metal?
Child wouldn’t receive any charge.
Charge will pass through the metal to earth.
Explain why the reading on the balance decreases
Road attract.
Upwards force
When the student brings the two rows closer together, the reading decreases further.
The attraction force increases
as the distance between the charges decreases.
Explain what happens as the roads were rubbed with the clothes
electrons Move between the cloth and rod.
Where electrons gather becomes negative.
Where electrons move away from becomes positive.
Arrangements and motion of solid.
Regular pattern vibrate in fixed positions, closely packed.
Liquid
Irregular pattern, flow over each other, closely packed.
Stay and explain the variables needed to calculate specific capacity of water.
Mass of water. Change in temperature. Energy from heater.
Measure temperature at the start and at the end
measure the mass of the anti cup and mass of the cup plus the water.
Zero scale with empty cup before adding H2O.
Use start and end readings on joulmeter.
Calculation of specific latent heat using the method may give a value that is different to the true answer. Explain why.
Energy may have been lost from water bath to surroundings.
This would increase energy.
Since energy is directly proportional to latent heat, this would increase the value of specific latent heat.
Expands its temperature decreases. Explain how this affects the pressure of the gas.
Pressure decreases,
molecules slowdown.
The collisions with container walls are less frequent.
There is a smaller force.
Some of the gas molecules dissolve into the cream. Suggest how this affects the pressure of the gas and the space above the cream.
Pressure decreases.
There are fewer molecules colliding with the walls.
Smaller force from molecules.
Explain how gas particles produce pressure on the walls of the spray can.
Particles collide with the wall.
Continuously hitting the wall. Producing a force.
Pressure =force / area.
Explain what happens to the gas pressure in the spray can as the liquid leaves.
Gas pressure decreases.
Gas molecules stay constant.
Gas volume increases.
Inversely proportional to volume.(pv=constant)
Particles collide with the wall less frequently.
why is the cool balloon is much smaller than the warmer one.
Particles move at a lower speed so less kinetic energy
On average.
Particles hit the size of container less frequently with less energy.
Reduces the pressure.
Tension in balloon pulls balloon to smaller size.
Investigate link between temperature and size of balloon. Identify 3. Possible faults and suggest improvements?
diff time in freezer does not give range of temperatures
Improve by using a water bath set to a range of temperatures.
Measure size is too vague.
measure volume, length, diameter, circumference.
Difficult to measure size with a ruler.
Measure the volume of water dissipated.
Repetitions do not make it a fair test.
Control variables.
Balloon may warm up. So take measurements quickly.
Alpha particle scattering experiment.
Environment.
A vacuum. Because alpha particles absorbed by short distances in air.
Explain readings of alpha scattering experiment
Small proportion deflected at large angles.
Shows that the mass and charge are concentrated in the nucleus.
Majority went straight through.
Most of atom is empty space.
Charge of the nucleus.
Positive because the alpha particle is positive and repelled at an angle
What is excitation?
Electrons gain enough energy to move up an energy level.
Hasn’t left the atom.
What is ionization?
Removal or addition of electron when given energy.
Explain how scientists can use radioactivity to find the age of a piece of granite. (4)
There is a known activity when rocks are formed.
Scientists can measure the activity now.
Activity can be compared with the original activity.
Scientists can determine the The number of half lives that have gone.
Calculate the age of granite through knowledge of half life.
Suggest why the age of a piece of granite could not be found using a uranium isotope with a half life of 15 hours.
Half life is short.
Age cannot be determined because the uranium would have already decayed.(would be too small to distinguish from background radiation.)
Isotope.
Same number of protons but different number of neutrons.
They do not emit radiation.
Describe what happens the number of protons and neutrons of 210Pb decays to 210Bi
A neutron has become a proton in this decay.
Proton number increase by 1.
Neutral number decreased by 1.
Beta decay.
Why does the mass and atomic number not change when a gamma is emitted?
Gamma is not a particle,
has no mass, no protons or neutrons,
so no particles lost when gamma ray is emitted.
Gamma is electromagnetic radiation.
How Much does the number of a particle reduce after two half lives
2^2 = so reduced by 4
Pro and con of peer reviewed research
Findings from experiments are looked over by other scientists.
Other scientists can learn from findings.
and check for accuracy
Injection solution of technetium 99 radioactive isotope detector attack. Patient has a short half life. Explain why isotopes that emit alpha particles or beta particles are not suitable for this.
Not enough penetration range.
Would be absorbed by air.
So more likely to cause cancer and themselves.
Suitable half life to use for radioactive tracer?
Long enough to carry out procedure.
Short enough to not ‘cause any long term damage.
