Physics, Chemistry and Biology: Post your doubts here!

[shafayat]

I think i can help more in phy and chem but in bio i will try as much as i can
wat exactly to u need??

n btw can I also use these resources

 

[always-smile :)]

aww.. so damn sweet of u ...
some r pastpapers doubts and some are explanations ...

to start with ! if we are diluting something its concentration changes? and if it does does its volume changes ? n if its an acid !! its strength changes?

no problem
yes because concentration is about the amount of water found in the sub. ..... yes because we add water so it will be the volume of sub + volume of water added.......no it doesn't change (( a strong acid stay strong even if it is dilute ))

 

[always-smile :)]

n btw can I also use these resources

n btw can I also use these resources

of course u can

 

[always-smile :)]

these r the most important things u need 2 knw in chem
then i will give u the summarized lessons which r in paper 6

this lesson represents a huge part in chem specially in paper 6

 

[Snehal12]

hiii i m facing a doubt in bio as im nt sure of the answer... its a may/june 2000 paper 3, no. 2 sum1 plz help ... asap

 

[Iridescent]

look at this relation ----> when we test for iodine or bromine ions we use silver nitrate
so make the inverse ((( to test for silver ions use iodine )))

results?

 

[sma786]

use the values u recorded in b
in exp 1 the final =32 and the initial=0 the difference = 32
in exp 2 the final 35 and the initial=19 the difference = 16
so the amount used in exp 2 is double the amount used in exp 1
so the ans. is exp 1 has the amount used in exp 2 (x2)

oooh lol dats so simple thanks =]

 

[sma786]

try this

heyy thanks alot =D thankuuuu

 

[Iridescent]

Explain why recycling aluminium is easier than recycling scrap iron?

 

[always-smile :)]

oooh lol dats so simple thanks =]

ur welcome

 

[always-smile :)]

results?

yellow precipitate

 

[sma786]

Helpss...
http://www.xtremepapers.com/CIE/Cambridge IGCSE/0620 - Chemistry/0620_w09_qp_6.pdf
Question 4, (e)

 

[tribianni]

plzz help me out physics 31........
parts of a motor nd thier functions .....
like wth is comutator?

 

[shafayat]

Helpss...
http://www.xtremepapers.com/CIE/Cambridge IGCSE/0620 - Chemistry/0620_w09_qp_6.pdf
Question 4, (e)

4 e 1 ) the reaction would be faster i.e it would take less time !!
4 e2 ) the highest tempreture reached would be less as there will be more medium ( sulfuricacid) for the heat to bo dispenced
4 e 3) while reading the thermometer ! while using thw measuring cylinder !

 

[shafayat]

plzz help me out physics 31........
parts of a motor nd thier functions .....
like wth is comutator?

a commutator is the contact between the rings and the carbon brush ! it keeps the current flowing in to the circuit when the rings still turns

 

[afshinsalim]

Mine Was So Good Actually I Think The Exam Was So Easy...Well Apart From The Onion Thing....

I wrote that the first onion cell drew in water but the second 1 became flaccid because there was a higher concentration of water inside the onion than outside. There was no change in the 3rd 1. I dont know if its ryt but i just wrote it.

 

[Lost_Life]

guys can anyone explain to me the mineral requirments for a plant BIO PP3

 

[Lyfroker]

i want the chemistry marking scheme of paper 1, 3 & 6 year 2000-2002

 

[always-smile :)]

I wrote that the first onion cell drew in water but the second 1 became flaccid because there was a higher concentration of water inside the onion than outside. There was no change in the 3rd 1. I dont know if its ryt but i just wrote it.

i wrote the same thing

 

[always-smile :)]

guys can anyone explain to me the mineral requirments for a plant BIO PP3

it needs nitrates to make amino acids ,, magnesium to make chlorophyll and phosphorus to make DNA
HOPE I HELPED