Biology; Chemistry; Physics: Post your doubts here!

[Ahmed Raja]

How does a relay circuit work?

 

[Catalan Osama Naved]

what is thermonic emission?

 

[Suchal Riaz]

what is thermonic emission?

the electrons are attracted to the nuclei so they can not escape. they are repelled by the negative charge but they don't have enough energy. a heater excites the electrons so they escape.

 

[Catalan Osama Naved]

thnx

the electrons are attracted to the nuclei so they can not escape. they are repelled by the negative charge but they don't have enough energy. a heater excites the electrons so they escape.

 

[inquisitiveness]

An atom of one of the isotopes of sodium contains
11 protons, 11 electrons and 13 neutrons

What can you say about the chemical properties of the different isotopes of sodium?
its the last Q in http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Physics (0625)/0625_w10_qp_32.pdf
and please explain your answer
thanks!

 

[sweetiepie]

http://www.xtremepapers.com/community/threads/o-level-notes-center.11138/ check these for notes might help u

 

[Unique@work]

plz guys tel me a way fom wich i can score straight A*...................
P.S:REPLY SOON..........

 

[usman]

A facebook group for Further Maths, intended to remove your doubts and solve your problems. Check it out:-

http://www.facebook.com/groups/furthermathsprodigies/​

 

[robinhoodmustafa]

plz guys tel me a way fom wich i can score straight A*...................
P.S:REPLY SOON..........

Study Well.

 

[Alice123]

can any1 write down similarities n differences between absorption and action spectrum?
thanks in advance

 

[VоrtεX 7.o]

can any1 write down similarities n differences between absorption and action spectrum?
thanks in advance

what is action spectrum? :O
never heard of it

 

[Suchal Riaz]

what is action spectrum? :O
never heard of it

he must be talking about a level. absorption light of different wavelength is in quantum mechanics which is not in syllabus.

 

[Suchal Riaz]

what is action spectrum? :O
never heard of it

he must be talking about a level. absorption light of different wavelength is in quantum mechanics which is not in syllabus.

 

[Alice123]

how to separate chloroplast pigments using chromatography... helppp!!!
Thanks in advance

 

[HarithAslam]

Hello there,
I'm having some trouble with the O/L Oct Nov 2012 Bio P12 Q37
What are homogenized bacteria?

 

[HarithAslam]

^oops, paper 11 not 12

 

[Muhammad Ali Khan]

I am a student of O-levels. Therefore, I need some definitions of Physics on the topic of:

1:Measurements
2:Kinematics
3:forces
4:Mass, Weight and density
5:Turning effects of forces
guyz, I need the detailed definitions and furthermore definitions related to this topic..plz.

 

[sweetiepie]

I am a student of O-levels. Therefore, I need some definitions of Physics on the topic of:

1:Measurements
2:Kinematics
3:forces
4:Mass, Weight and density
5:Turning effects of forces
guyz, I need the detailed definitions and furthermore definitions related to this topic..plz.

https://www.xtremepapers.com/community/threads/o-level-notes-center.11138/ check here

 

[TheStallion-Reborn]

Hey! Can anyone please xplain question number 31 & 37 of Physics M/J 2011 paper 12!

 

[fatima0000]

hi, i want revision checklist for biology 5090