AQA A LEVEL PHYSICS PAPER 1
1.What is meant by work function (2): Minimum energy required by an
electron to escape from (1) a metal surface (1)
2.What is meant by ionisation energy? (2): Minimum energy required to
remove an electron from an atom (1) from the ground state (1)
3.Why do emitted electrons have a kinetic energy that varies up to a
maximum value? (4): Energy of a photon is fixed/constant (1)
Energy is required for electrons to overcome work function ø (1)
Electrons deeper into/below the surface of the metal require more
energy to over- come work function and therefore have less KE(1)
Maximum KE = Energy of photon - work function ø (1)
4.Explain how (bright ring) diagram is evidence of the wave-particle duality
of electrons?: Diffraction pattern maxima/minima (bright and dark
areas) (1) Diffraction is a property of waves- proves wave-behaviour of
electrons (1)
5.What is meant by the ground state?: The lowest energy state of an atom
6.Explain the difference between excitation and ionisation (2): An
electron receives a discrete amount of energy for BOTH (1)
Excitation promotes an electron to a higher energy level
Ionisation is when an electron receives enough energy to leave the atom
7.Explain why only photons of certain frequencies cause excitation (4):
dis- crete energy levels (1)
Electrons need to absorb a DISCRETE amount of energy to move to a
higher energy level (1)
1/
7
, Photons need to have a certain frequency to provide this energy,
because E=hf (1) interaction is a 1:1 reaction all of the photon's energy
is absorbed (1)
8.Explain how excitation takes place in a fluorescent tube: Electrons
flow through the tube to the applied PD causing a current to flow
(1)
Electrons collide with mercury atoms in the tube (1)
This raises electrons in the mercury atom to a higher energy level (1)
9.What is the purpose of coating in a fluorescent tube?: UV/ High energy
photons emitted from mercury atoms when the electrons in the atom
de-excite (1) High energy photons absorbed by the coating (1)
Coating emits photons in the visible spectrum (1)
10.What happens when annihilation occurs? (2): particle and an anti-
particle collide and cease to exist (1)
Their mass is released as energy in the form of a pair of gamma photons
(1)
11.How does the strong nuclear force between two nucleons vary with
the separation of the nucleons? (3): repulsive at < 0.5 fm (1)
attractive from 0.5 to 3 fm (1)
above 3 fm, force 0 (1)
2/
7
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller TIPSCORE. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £10.53. You're not tied to anything after your purchase.
