Unit 1 AS AQA Physics

Hello All,

just a few questions....

1) if a electron is excited is this only by a photon with the energy equal to the energy difference between the two states? or can it be excited by another electron with this energy also? sorry my book just confused me a bit on that one.

2) Can someone please ask me some unit 1 particle questions I need some practice please ? thanks if you don't mind

Many thanks and good luck!

Will

Reply 1

Stonebridge

13

Original post by Billsonbubbles

Hello All,

just a few questions....

1) if a electron is excited is this only by a photon with the energy equal to the energy difference between the two states? or can it be excited by another electron with this energy also? sorry my book just confused me a bit on that one.

Will

A photon will need exactly the right amount of energy (equal to the difference between the two levels) to excite the bound electron to the higher level. The photon is then destroyed.

A free electron can collide with an atom and give some of its energy to the bound electron to excite it to the higher state. It will lose that particular amount of energy and then continue on its way after collision with that much less energy than it had before.

Reply 2

Krollo

17

An omega minus particle has strangeness -3.

i) What is its quark structure?
ii) Deduce its charge, lepton number and baryon number.

Posted from TSR Mobile

Reply 3

Billsonbubbles

OP

5

Original post by Krollo

An omega minus particle has strangeness -3.

i) What is its quark structure?
ii) Deduce its charge, lepton number and baryon number.

Posted from TSR Mobile

Thanks so much !

I think because an omega is a baryon it has three quarks , and as it has a strangeness of -3 this means that it has three strange particles thus it's quark combination is SSS , and because it is a baryon it has a baryon number of 1 and a charge of 3 x - 1/3 which is -1 , and it is neither a lepton or anti lepton thus it has a lepton number of 0 is this right ?

Reply 4

Krollo

17

Original post by Billsonbubbles

Thanks so much !

I think because an omega is a baryon it has three quarks , and as it has a strangeness of -3 this means that it has three strange particles thus it's quark combination is SSS , and because it is a baryon it has a baryon number of 1 and a charge of 3 x - 1/3 which is -1 , and it is neither a lepton or anti lepton thus it has a lepton number of 0 is this right ?