Core Science Flashcards
How many times smaller is the nuclear radius than the atomic radius
10,000 x
What are the inner 3 shells of an atom labelled as and how many electrons can they each hold
K = 2
L=8
M=18
what determines the energy level of a particular shell and how
dependant on number of protons in atom (more protons= more tightly bound electrons)
Why are outer shells less tightly bound than inner shells
shielding effect from other electrons
A X label this
Z
a= atomic mass
z= proton number
x= element
define 1 atomic mass unit
mass of 1/12th of carbon-12
Some of an elements mass is lost in mass defect which represents the binding energy of its constituent nucleons because E=MC^2, energy and mass are interchangeable
Define isotope
the same element having same number of protons but different number of neutrons, hence still having same chemical properties and energy levels
what is the equation for wavelength?
wavelength= speed of light / frequency
What is the speed of light
3x10^8ms
How do you calculate the energy of an electromagnetic wave?
energy (j) = frequency(m) x planks constant
E = hf
How many joules is in 1eV?
1x10^-19 j
1eV = kinetic energy of electron gained by applying potential difference of 1 volt to it in a vacuum
Define mono-energetic and poly-energetic beams , give eg’s
Mono-energetic = only contain electromagnetic radiation of ONE energy e.g laser
Poly-energetic = conatains electromagnetic radiation with RANGE of energy (spectrum) e.g x-rays from X-ray tube
Define ionising radiation
an electromagnetic wave that carries enough energy to knock an electron from an atom
