Biology; Chemistry; Physics: Post your doubts here!

[Spidey21]

yayee..

 

[Asif1223]

can u suggest me any sites where i can find notes on health and disiease

 

[Raikko]

Assalam-o-Allaikum and Hi everyone ,

hope u all are doin great !

Well as the topic says help for chemistry biology and Physics is available here that means that u can ask any mind blowing question or ask any question regarding a particular topic or ask abt any questions from Past paper or any of your text books.

I made this topic so that people dont make many posts asking abt bio,physics or chemistry individually but they can post their reply here where it can be answered with ease and the members wont have to go searching for topics to help! !

So what are u waiting for now write ur questions here !
THANKS and Bye or Allah Hafiz ! :wink: :good:

Plx some body in this forum help im a student studying in grade 10..... wishing to finish my home work knowingly

My first question is
1-Aluminium has a density of 2700Kg/m³.
a) What is the density in g/cm³?
b) What is the mass of 20cm³ of aluminium?
c) What is the volume of 27g of aluminium?

Use the information in the table of densities at the top of the page to answer the following:
2) What material, of mass 39g, has a volume of 5cm³ ?
3)What is the mass of air in a room measuring
5m x 2m x 3m?
4)What is the volume of a storage tank which will hold 3200kg of petrol?
5)What mass of lead has the same volume as 1600 kg of petrol?

 

[Translucent231]

paka pakaya halwa chahye bas kameenay sust bachon ko

 

[MustafaMotani]

paka pakaya halwa chahye bas kameenay sust bachon ko

xD

 

[Aneesraja23]

account for the following :
a ) a saucepan used in cooking has a low heat capacity.
b ) on a clear sunny day , the temp of the surface of the sea rises less rapidly than the temp of nearby land .

Ans a: Heat transfer will take place through both convection and conduction; more effective.
Ans b: Radiation will only heat the surface of the water, this will not affect the rest of the water because convection currents do not travel downwards; therefore it remains relatively cool.

 

[scouserlfc]

Ans a: Heat transfer will take place through both convection and conduction; more effective.
Ans b: Radiation will only heat the surface of the water, this will not affect the rest of the water because convection currents do not travel downwards; therefore it remains relatively cool.

One or two things i think u already know but i think these might help if u dont know

Although the answer to the first part looks absurd as it doesnt answer the question but in the second part u say convection currents dont travel down actually they do cold convectional currents travel down thats exactly how an air conditioner works and also in the second part u say that radiation just heats the top part,actually radiation here which is concerned with Infra-red radiation heats up the whole water but it heats up very slowly due to its very high specific heat capacity therefore water is mostly used as a coolant

Hope u dont mind wanted to correct the concepts

 

[gelato]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_1.pdf
Why is number 12 A and not B?

 

[ashiqbal]

account for the following :
a ) a saucepan used in cooking has a low heat capacity.
b ) on a clear sunny day , the temp of the surface of the sea rises less rapidly than the temp of nearby land .

a so that its temp increase quickly and can help cooking

b . becox heat of capacity of land is greater than that of sea

i think that the heat capacity of land is less than the heat capacity of sea, that is y it heats up quickly!

 

[ashiqbal]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_1.pdf
Why is number 12 A and not B?

copper metal gives electrons at positive terminal(anode) to become Cu2+ ions. the ions then travel to the negative terminal(cathode) where they gain electrons and turn back into copper metal. Remember that the object to be plated is always made the cathode(connected to -ve terminal)

 

[ashiqbal]

yayee..

yeh 7 - chapters kia cheez hai?

 

[MustafaMotani]

i think that the heat capacity of land is less than the heat capacity of sea, that is y it heats up quickly!

yeah sorry i meant that only xD

 

[MaboroshI_I]

Anyone know how many marks we need to score in all 3 papers (for all 3 sciences) for an A*?

 

[ashiqbal]

Anyone know how many marks we need to score in all 3 papers (for all 3 sciences) for an A*?

dude, there are no fixed marks. they change it every year

 

[Spidey21]

yeh 7 - chapters kia cheez hai?

check karlo..
mera homepage hai yahan par
mere profile par ja kar check karle yar..

 

[MustafaMotani]

check karlo..
mera homepage hai yahan par
mere profile par ja kar check karle yar..

Link to dena.. ??

 

[SalmanPakRocks]

English only guys.

 

[ashiqbal]

English only guys.

OK sir!!

 

[Nilza]

Hi.... When will the 5070 Chemistry June 2012 Questions Paper will be available?

 

[ashiqbal]

Hi.... When will the 5070 Chemistry June 2012 Questions Paper will be available?

after result in august i guess, which is 13 august