Particles Of Matter Flashcards
Density meaning
How a compact mass is in a material or object
Density equation
Density = mass / volume
How to calculate volume of any iregaular object
Can only be measures using a displacement/eureka can.
Solid state of matter description
Regular arrangement(lattice)
Vibrate in fixed positions
Cannot be compressed
Liquid state of matter
Particles have no regular arrangement and able to move past each other
Cannot be compressed
Gas states of matter
Particles are far apart move randomly at fast speeds(high energy)
Can be compressed
What is solid to gas change
Sublimation
What must be supplied to melt/evaporate
Energy(heat) must be supplied to overcome the electrostatic forces of attraction between particles
Internal energy
The sum of kinetic energy and potential energy of all particles in a substance
Particles theory of gasses
Gas pressure is a result of particles colliding with the walls of the container, exerting a force outwards.
What happens when you heat a gas
You increase the particles kinectic energy, meaning they collide more frequently and with a greater force:there is an increase in pressure
What is the relationship between pressure and volume of gasses
Inversely proportional
What is an isotope
Different number of neutrons but same number of protons
What happens to unstable nuclei
They will decay to become more stable, emitting radiation in the process. These can ionise other atoms/molecules.which can be dangerous
What is gamma radiation
Is a high energy EM wave that can be emitted by a nucleus, but this isn’t due to decay;it’s just due to a nucleus having excess energy
Alpha decay
The emission of a helium nucleus from a unstable nuclei
Alpha radiation described(what is it-mass-charge-ionising power-penetrating ability-use)
Helium nucleus/atom
Mass=4
Charge=2
High ionising power
Low penetrating abillity(absorbed by paper/few cm of air)
Use-smoke detector
Beta radiation(what’s is it-mass-charge-ionising power-penetrating ability-use)
Fast moving electron
Mass - 0
Charge - -1
Medium ionising power
Medium penetrating abillity
Use - thickness gauge
Gamma radiation(what is it-mass-charge-ionising power-penetrating abillity-use)
High energy EM wave
Mass - 0
Charge - 0
Ionising power low
High penetrating abillity
Use - radiotherapy/gamma knife and sterilisation
Radioactivity definition
The rate of decay in a sample of radioactive material. This is equal to the rate of radiation emitted
Half life
The time taken for the activity to halve(this is also true for number of unstable nuclei left, and also masss.
Fission definition
Splitting of a nucleus into two daughter nuclei, releasing energy.(mostly kinetic/heat) that can then used to generate electricty.
How is fission induced
By a neutron absorbing a neutron making it more stable it also releases up to 3 more neutrons - these go on to induce more fission. This is a chain reaction.
Fusion
The joining together of two (Lighter) nuclei(such as heavy hydrogen-2) releasing energy(kinetic and EM radiation)
What happens in both fission and fusion
In both cases, the total mass of the particles decreases:mass has been converted to energy
