Physics GCSE Flashcards
What is Density?
Mass divided by volume
What is a vernier calliper?
A measuring device, watch you tube video on how to use it.
What are the two ways internal energy can be stored?
Kinetic energy of the atoms or the potential energy in the bonds.
What happens to the temperature of a substance when it is changing state?
It doesn’t change as all the energy is going into potential energy by reorganising the molecules.
Why does ice float on water?
Because water molecules in a solid are less dense than water.
What does the gradient/steepness mean in a temperature/time graph?
If a line in a temperature time graph is very steep there is a low amount of energy needed for a change of state, as it takes less time. If you need a high amount of energy, the line will be shallower.
What is the equation for thermal energy?
Change in = mass x specific heat x temperature
thermal energy capacity change
How do you calculate the energy needed for a change of state?
mass x specific latent heat of state
What is internal energy made of?
The store of all the molecules in the substance and the potential energy between the molecules.
What is pressure?
Pressure is caused by the collision of gas particles on the wall of a container. The higher the pressure, the more collisions.
Pressure is always at a perpendicular angle to the surface.
How does temperature affect pressure.
If the temperature increases, while the volume stays constant, the pressure will increase. This is because the store of kinetic energy will increase so there are more collisions, causing higher pressure.
How are volume and pressure related?
They are inversely proportional ( P ip2 1/v, V ip2 1/p, PxV = constant)
What is radioactive decay?
Radioactive decay is when some atomic nuclei are unstable, so in order to become more stable they release radiation. It is random and can’t be predicted.
What is alpha decay?
Alpha is a particle, it is also the nucleus of a helium atom (2 protons, 2 neutrons). It is the most ionising out of the three radiations, but travels the least, as it can’t travel through anything thicker than 2cm of air.
What is Beta radiation?
Beta is a particle that is a fast moving electron. It is not called an electron as it comes out of the nucleus. It has a small relative mass, is less ionising than alpha, but more than gamma, and can travel through air but not card or foil (Can travel further than alpha but less far than gamma.
What is gamma radiation?
Gamma is an electromagnetic wave.It has no relative mass and does not have charge. It has a low ionising power but can travel the furthest out of the three classic forms of radiation.
What happens in Beta decay?
A neutron splits into a proton and an electron. The resultant product also goes up by a proton.
What is activity?
The nuclei that decay in a substance per second.
Activity = Number of decays
_________________
Time
How does increasing the temperature of a substance affect its activity?
It doesn’t. Temperature does not increase decay but increasing the mass of the sample does.
