Physics, Chemistry and Biology: Post your doubts here!

[sundas]

What is produced as a result of decomposition apart from carbon dioxide?

 

[sundas]

What is released as a result of decomposition apart from carbon dioxide?

 

[7alawa]

What is released as a result of decomposition apart from carbon dioxide?

methane

 

[7alawa]

hey i was solving a chemistry paper, and had this doubt:
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_32.pdf
question number: 3 a (ii)
I know the answer ( through the marking scheme ofcorse), but i am yet not able to figure out how to solve it

well it is clear that the volume of thiosulphate in 4 is one fifth of the volume of thiosulphate in exp. 1 so just multiply the time of exp. 1 by 5 and u get the answer for experiment 4

 

[Kaulish Mehta]

have a look at the volume of thiosulfate 50 and 25
two time of 25 is 50 so 25*2 is 50
look at there time now 48 and 96
double of 48 is 96 so 48*2=96
Now at 40 and 10
four times 10 is 40 that is 10*4 is 40
so 60*4 will give you your answer
I hope i helped

Thank you, it really did

and can you help me with question 7 b (iii) too, of the same paper,
website( incase you need it) : http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_32.pdf

 

[inquisitiveness]

Choose a different element from Period 3 that matches each description.iii) It has a gaseous oxide of the type XO2, which is acidic.
why is the answer chlorine D:

 

[ZaqZainab]

Development is a progressive change the child undergoes which increases the physical, social, mental and emotional capacities of the child.
where as Growth usually refers to a noticeable increase in the size of the organism or a specific part of the organism. You can observe it with a naked eye. Growth is a type of development.
Want examples Huh?? during early human development (right after birth), the neurons in the brain start to make critical connections, which give later adult functions, such as vision. This is considered as a DEVELOPMENT, but it is usually not regarded as growth, because
1) you cannot observe it without advanced instrument
2) it doesn't cause increase of size of anything.
For Growth you nail's you see them growing this is an example of growth

 

[tweetie]

8 is retraction obviously it needs more energy like when you run your leg muscles contract so you need more oxygen you see how fast you breath.the one leaving without contraction is 6 so it is suppose to be less! which is the only option 40
13 Lipase produced in the pancreas and secreted into the small intestines through pancreas so duodenum is nearest to the pancreas so yeah that's why it is the most
16 you have to lean this that the walls of the LEFT OF THE HEART(right of yours which is Q) are thicker than the RIGHT SIDE OF THE HEART
20 yeast produces CO2 in the absence of Oxygen that's what makes the break rise. the term used is aerobic which means breathing in the absence of oxygen
40 the river is flowing with out any change then adding the sewage decreases the oxygen and increase the mineral ions this is done only at the starting and then you see the levels come back to normal
I hope i helped

oooo thnx a lot u made me understand everything...thank u but u didnt answer q28.......well thnx

 

[ZaqZainab]

oooo thnx a lot u made me understand everything...thank u but u didnt answer q28.......well thnx

oh missed it for this one you need to know what is development you can refer to my last post here

 

[sundas]

apart from these two is water released or nitrogen?

 

[ZaqZainab]

Thank you, it really did

and can you help me with question 7 b (iii) too, of the same paper,
website( incase you need it) : http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_32.pdf

Here you need to know the methods and why they are used sorry i can't actually explain but here is a link to help you out

 

[ZaqZainab]

Thank you, it really did

and can you help me with question 7 b (iii) too, of the same paper,
website( incase you need it) : http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_32.pdf

I can't explain you all that but here is a link http://www.docbrown.info/page03/AcidsBasesSalts06.htm

 

[mendezgoon]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s10_qp_32.pdf

For Question 2(b), How am I supposed to draw the carbohydrate?

 

[sj0007]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s10_qp_32.pdf

For Question 2(b), How am I supposed to draw the carbohydrate?

-o-box-o-box-o-

 

[mendezgoon]

-o-box-o-box-o-

Thanks

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w10_qp_32.pdf guys question 1 d and e tell me how to do it please.

 

[ZaqZainab]

does anyone has da markscheme of oct/nov 2002 igcse biology paper 1

Here 1 C 21 D
2 D 22 B
3 B 23 D
4 C 24 C
5 D 25 A
6 A 26 C
7 D 27 C
8 C 28 A
9 A 29 A
10 B 30 B
11 A 31 B
12 A 32 D
13 D 33 C
14 B 34 C
15 B 35 A
16 A 36 D
17 A 37 B
18 D 38 D
19 B 39 B
20 B 40 A
LOL Could not find a proper one

 

[ZaqZainab]

Thanks a lot! Can u help me with this question with explanations why the other choices are wrong..
What is the best measurement to determine the growth of seedlings? A- the dry mass of the whole seedling
B- the height and with of the parts above ground C- the length From the Root tip to the stem tip D- the total number of leaves

I Really don't know the answer but i would say A
of course it is not B some plants like radish grow under the ground
C some plants are growing but not really changing the length what if it is the width
D some plants don't even have leaves well like a cactus it does but you know what i mean!

 

[ZaqZainab]

Thanks a lot

you are welcome i hope you understand the MS

 

[ZaqZainab]

do u hav da markscheme of june 1993 igcse biology paper 1

http://www.freeexampapers.com/index...2003/Answers June 1993 -- 2003 P1, 3, & 6.pdf