Biology; Chemistry; Physics: Post your doubts here!

[exploded diper]

2007 onwards.They're really short so they aren't that time consuming.I also read physics atp from 1992-2003.

where did u find papers before 2000....

 

[funky brat]

I just found them some where on XPC, Biology ATP notes.

 

[ZohaKhan]

b) Describe the ways in which a plant obtains its oxygen for respiration.
need a good answer fr ds?? nyone?

 

[exploded diper]

Javert: Now bring me prisoner 24601, your time is up and your parole’s begun. You know what that means?

Valjean: Yes, it means I’m free.

Javert:

 

[asadalam]

where did u find papers before 2000....

I have a really old book

 

[asadalam]

guys is this curve acceptable?also do we have to label the arrows with the axis like arrow with time and current,do we have to draw it?

 

[ZohaKhan]

b) Describe the ways in which a plant obtains its oxygen for respiration.
need a good answer fr ds?? nyone?

 

[Happy Muslimah]

Which application may use the part of the electromagnetic spectrum called microwaves?
A cooking vegetables (this is the correct answer)
B detecting small cracks in metals
C gaining a sun-tan
D lighting a fluorescent tube

can anyone explain me
funky brat

 

[asadalam]

Which application may use the part of the electromagnetic spectrum called microwaves?
A cooking vegetables (this is the correct answer)
B detecting small cracks in metals
C gaining a sun-tan
D lighting a fluorescent tube

can anyone explain me
funky brat

B is using X rays which detect cracks
C is using UV rays
D is also using UV rays i think.

And obviously we have used microwaves in cooking foods so A is the answer

 

[Happy Muslimah]

B is using X rays which detect cracks
C is using UV rays
D is also using UV rays i think.

And obviously we have used microwaves in cooking foods so A is the answer

thankyou..

 

[Awesome12]

View attachment 40562
guys is this curve acceptable?also do we have to label the arrows with the axis like arrow with time and current,do we have to draw it?

the question asks to make a line of best fit, but your line is going through like all the points. Tell me the paper, i will make one and upload it here

 

[***amd***]

B is using X rays which detect cracks
C is using UV rays
D is also using UV rays i think.

And obviously we have used microwaves in cooking foods so A is the answer

but isnt it infrared used to radiate heat?

 

[***amd***]

b) Describe the ways in which a plant obtains its oxygen for respiration.
need a good answer fr ds?? nyone?

by diffusion through stoma, by using the oxygen produced in photosynthesis, by the air in pores in the soil, and by directly through the outer air (as used by lower epidermal cells of leaf).
thats all, i guess.

 

[asadalam]

the question asks to make a line of best fit, but your line is going through like all the points. Tell me the paper, i will make one and upload it here

s11 p41 physics

 

[***amd***]

http://papers.xtremepapers.com/CIE/...l O Level/Chemistry (5070)/5070_s13_qp_12.pdf
Q11, Q25, Q32, Q33

http://papers.xtremepapers.com/CIE/...l O Level/Chemistry (5070)/5070_s13_qp_22.pdf
A5 (b)
B7 (a)
B8 (g)

 

[Lilly2318]

Physics :
(h) discuss the environmental and cost implications of underground power transmission compared to
overhead lines.

 

[Lilly2318]

what is the use of millibar ?

 

[FLRNAB]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_s13_qp_12.pdf
Q11, Q25, Q32, Q33

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_s13_qp_22.pdf
A5 (b)
B7 (a)
B8 (g)

11)B
X2 + H2 --> 2HX.
Just read the question and translate the words into a equation.
"One volume of a gaseous element X2" -> 1X2
"an equal volume of gaseous hydrogen" -> 1H2
"form two volumes of a gaseous hydride" -> 2HY

25) "proton number between 21 and 30" --> See the periodic table and these elements are Transition Metals.
Unique Properties of Transition Metals:
1) Form Colored Compounds --> "4. forms two coloured sulfates."
2) Have variable valencies --> "3. forms two basic oxides"
So D

32) C - See Colors of Cations in Syllabus
Blue color of Cu2+ ions
Zinc will displace Hydrogen from HCL as it is more reactive making ZnCl2. Red-Brown can't be the residue because that is color of Iron (III) ions so only option left is grey.

33) B
1) Ar of Nitrogen = 14
Mr of Urea = 60, Percentage by mass = 14/60 * 100 = 23%
Mr of Ammonium nitrate = 80, Percentage by mass = 14/80 * 100 = 17.5
So proportion of nitrogen by mass in Urea is Higher than Ammonium Nitrate.

2)
Moles of Nitrogen in Urea = CH4[N2]O = 2
Moles of Nitrogen in Amm. = [N]H4[N]O3 = 2
So Equal

A5) B) Vanadium is a transition metal so it will form colored compound so solution will be colored.
B7) A)

+ Stopwatch
B8) G) Carbon Monoxide and Water

 

[exploded diper]

I have a really old book

ohh

 

[exploded diper]

but isnt it infrared used to radiate heat?

they both can be used for heating in cooking .....there are infra red(chula) and microwaves oven