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level: Level 1

Questions and Answers List

level questions: Level 1

Question	Answer
1 power of 10	order of magnitude
particles which make up matter	fermions
particles which give rise to forces (force mediating particles)	bosons
particles which exist on their own	leptons
group which protons and neutrons belong	hadrons
what hadrons are made up of	quarks
made up of 3 quarks	baryons
made up of a quark and an anti-quark pair	mesons
protons quark structure	uud (+1)
neutrons quark structure	udd (0)
provides evidence for the neutrino	beta decay
6 quarks and 6 leptons which physicists believe are not made up of smaller particles	fundamental particles
holds particles of the same charge together. stronger than electrostatic repulsion that forces particles apart. gluon in the exchange particle	strong force
involved in radioactive beta decay. W and Z bosons are the exchange particles	weak nuclear force
stops electron from flying out the atom. exchange particle is the photon.	electromagnetic force
holds matter in planets, stars and galaxies. exchange particle is the graviton	gravitational force
when a particle and anti-particle meet, they...	annihilate each other
the strength of the field decreases as you move away from the charge	radial fields
field lines equally spaced between parallel plates, meaning the field strength is constant	uniform fields
shows where a positively charged particle would move	arrows
gives an indication of the strength of the force	spacing between field lines
cathode ray tube, paint spraying, photocopying/laser printing and pollution control are all...	uses of electric fields
1 joule per coloumb	1 volt
a measure of energy that has been transferred	work done
when a current flows through a wire a _______ is produced	magnetic field
the direction of the magnetic field depends on the	direction of current flow
particles are accelerated in a straight line using electric fields	linear accelerator
a combination of electric and magnetic fields are used to accelerate particles in a circular path	cyclotrons and synchrotrons
particle accelerators were invented to...	investigate the structure of the atomic nucleus
increase the speed of particles. the force is constant in a uniform electric field so the particles are accelerated in a straight line	electric fields
mass no. decreases by 4, atomic no. decreases by 2	alpha decay
mass no. unchanged, atomic no increases by 1 (converts down quark to an up quark)	beta decay
accompanies alpha and beta radiation with gamma radiation.	gamma decay
nucleus with large mass number splits into two nuclei, which have two smaller mass numbers. neutrons are released and it may be spontaneous or induced.	fission
mass is a form of	energy
when masses before and after fission/fusion are compared accurately, there is a	mass difference
the total mass before fission/fusion is_____ than the total mass of the product(s)	greater
decreasing mass causes an equivalent amount of_____ to be produced	energy
two nuclei combine to form a nucleus of a larger mass number	fusion
power per unit area	irradiance
emits radiations in all directions	point source
electrons are ejected from a metal surface when exposed to electromagnetic radiation	photoelectric emission
the minimum frequency required to cause photoemission	threshold frequency
the minimum energy required to remove an electron from a metal	work function
produced by electrons being shared between many atoms, giving a huge range of possible frequencies	continuous spectra
only light of specific frequencies and specific colours are produced. used to identify elements	line spectra
when photons of light pass through a gas, photons with the same energy as the energy gaps can be absorbed	absorption spectra
lowest energy level where the electron orbit is closest to the nucleus	ground state
when an electron gains energy and moves to a higher energy level, which is further away from the nucleus	excited state
when an electron has gained enough energy to leave the atom	ionisation state