Physics, Chemistry and Biology: Post your doubts here!

[za Shadow]

guyyyysssss what r the levels of trachea, bronchus, bronchiole and alveolus by that i mean cell tissue or organ??????????

HEEEEEEEELLLLLLLLLPPPPPPPPPPPPP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[areebaization]

guyyyysssss what r the levels of trachea, bronchus, bronchiole and alveolus by that i mean cell tissue or organ??????????

HEEEEEEEELLLLLLLLLPPPPPPPPPPPPP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

trachea, bronchus-organs
bronchiole and alveolus-tisuue
please confirm it

 

[za Shadow]

trachea, bronchus-organs
bronchiole and alveolus-tisuue
please confirm it

thxxx

 

[MNU]

this question was in may june 2005
15 Which substances are stored in the body of a healthy person?
substance
carbohydrate
fat
protein
and the answer is carbohydrates and fats only but why not proteins?

 

[MihirC]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_1.pdf

Question 19. The answer is supposed to be D, but I don't understand why.

 

[za Shadow]

this question was in may june 2005
15 Which substances are stored in the body of a healthy person?
substance
carbohydrate
fat
protein
and the answer is carbohydrates and fats only but why not proteins?

proteins are not stored at all they r broken down to amino acid remember??

 

[Ahmedm96]

nov o10 bio v1 cant understand why it is B not C

 

[Ahmed Khider]

ORGANS... I really hated this part about which is an organ and which is a tissue... !

Guys listen to Rahma Abdelrahman she knows best about this whole organ tissue thing

 

[Ahmed Khider]

hey thanks for the answers previouly .please can i know some more answers .thnx a lot in advance
may 1995 no. 2,10,20,31
oct/nov 1995 no. 17 ,18,31,35
may 1996 no.18,27,28
oct/nov 1996 no. 3,4,31
may 1997 no. 9,10,14,19,25,27,31,33
oct/nov 1997 no. 2,4,13,16,26,37
may 1998 no. 5,14,17
oct/nov 1998 no. 2,11,16,21,22,23,25,29,30,40

I guess im late now..u probably finished your exam

 

[Ahmed Khider]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_1.pdf

Question 19. The answer is supposed to be D, but I don't understand why.

The question shows that the oxidation state will remain the same as it says b4 and after the question
chromate(
VI
) so the answer is either C or D. KOH is an alkali(soluble base) and when an excess of any alkali is added the ph of the mixture increases so the answer is D

 

[MihirC]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdf

Question 13. Why is the answer D?

 

[Ahmed Khider]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdf

Question 13. Why is the answer D?

I dont understand this question too!!

 

[Ahmedm96]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdf

Question 13. Why is the answer D?

because chlorine bleaches Litmus paper so the other choices are wrong

 

[IGSCE.Geek.]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w08_qp_1.pdf
q 15 how come its A but not B?
please answer!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Maz]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w08_qp_1.pdf
q 15 how come its A but not B?
please answer!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Assalaamu alaikum.
When 5g of X was dissolved in 1000 cm3 of water,there was a temperature change of 10.
When dissolving in 500 cm3 of water it has lesser water particles to react with, therefore the temperature change would double.

 

[IGSCE.Geek.]

Assalaamu alaikum.
When 5g of X was dissolved in 1000 cm3 of water,there was a temperature change of 10.
When dissolving in 500 cm3 of water it has lesser water particles to react with, therefore the temperature change would double.

sorry to say but i don't understand what you mean..

 

[fishcook]

An excess of copper(II) oxide is added to dilute sulfuric acid to make crystals of hydrated
copper(II) sulfate.
The processes listed may be used to obtain crystals of hydrated copper(II) sulfate.
1 concentrate the resulting solution
2 filter
3 heat the crystals
4 wash the crystals
Which processes are needed and in which order?
A 1, 2, 3 and 4
B 1, 2, 4 and 3
C 2, 1, 2 and 3
D 2, 1, 2 and 4

COULD SOMEONE PLEASE EXPLAIN WHY ITS D..
wont it just become a solution since its soluble???​

 

[fishcook]

from the really old paper about some energy diagram is the answer endothermic or exothermic? and also for the hydrogen q., from the paper in 1990's?

Electricity from a power station passes through overhead cables to a substation and then to a
school where it is used to electrolyse concentrated hydrochloric acid using inert electrodes.
Which substances are used for the overhead cables and for the electrodes?
overhead cables electrodes
A aluminium copper
B aluminium platinum
C copper platinum
D platinum aluminium
WHY IS IT B.. isnt platinum suppose to be really expensive and schools can not afford it?​

 

[Maz]

An excess of copper(II) oxide is added to dilute sulfuric acid to make crystals of hydrated ​

copper(II) sulfate. ​

The processes listed may be used to obtain crystals of hydrated copper(II) sulfate. ​

1 concentrate the resulting solution ​

2 filter ​

3 heat the crystals ​

4 wash the crystals ​

Which processes are needed and in which order? ​

A 1, 2, 3 and 4 ​

B 1, 2, 4 and 3 ​

C 2, 1, 2 and 3 ​

D 2, 1, 2 and 4 ​

​

COULD SOMEONE PLEASE EXPLAIN WHY ITS D..​

wont it just become a solution since its soluble???​

An excess of copper oxide is added to the acid, meaning that the salt is added in such quantities that no more of the salt can dissolve in it anymore i.e the acid has become saturated.

 

[Maz]

from the really old paper about some energy diagram is the answer endothermic or exothermic? and also for the hydrogen q., from the paper in 1990's?

Electricity from a power station passes through overhead cables to a substation and then to a ​

school where it is used to electrolyse concentrated hydrochloric acid using inert electrodes. ​

Which substances are used for the overhead cables and for the electrodes? ​

overhead cables electrodes ​

A aluminium copper ​

B aluminium platinum ​

C copper platinum ​

D platinum aluminium ​

WHY IS IT B.. isnt platinum suppose to be really expensive and schools can not afford it?​

The question says inert electrodes, price isn't what we have to consider. And aluminium cause overhead cables are made of aluminium.