Physics, Chemistry and Biology: Post your doubts here!

[♣♣ Magnanimous ♠♠]

1 Air is a mixture of gases. The main constituents are the elements oxygen and nitrogen.
(a) (i) Name another element in air.
.............................................................................................................................. [1]
(ii) Give the formula of a compound in unpolluted air.
.............................................................................................................................. [1]
(b) Common pollutants present in air are the oxides of nitrogen and sulfur dioxide.
(i) How are the oxides of nitrogen formed?
...................................................................................................................................
...................................................................................................................................
.............................................................................................................................. [2]
(ii) How is sulfur dioxide formed?
...................................................................................................................................
...................................................................................................................................
.............................................................................................................................. [2]
(iii) These oxides are largely responsible for acid rain.
State two harmful effects of acid rain.
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.............................................................................................................................. [2]

so hello.......
a(i) the element is carbon-dioxide.
(ii) CO2.
b(i) Nitrogen oxides (NOx), such as nitrous oxide and nitrogen dioxide are formed by reaction of nitrogen with oxygen in the air used during combustion.
(ii) A range of sulphur oxides (SOx) are formed by reaction of sulphur impurities (or maybe additives) in the fuel with oxygen in the air SOx will form sulphuric or sulphurous acid that will also contribute to acid rain.
(iii)
Some plants are tolerant of acidic conditions, while others are not. Acidic soils may affect microorganisms in the soil, which play important roles in plant growth.
it effects the statues especially those which are made up of limeston......



I hope my answer helped you....

 

[muraqba]

so hello.......
a(i) the element is carbon-dioxide.
(ii) CO2.
b(i) Nitrogen oxides (NOx), such as nitrous oxide and nitrogen dioxide are formed by reaction of nitrogen with oxygen in the air used during combustion.
(ii) A range of sulphur oxides (SOx) are formed by reaction of sulphur impurities (or maybe additives) in the fuel with oxygen in the air SOx will form sulphuric or sulphurous acid that will also contribute to acid rain.
(iii)
Some plants are tolerant of acidic conditions, while others are not. Acidic soils may affect microorganisms in the soil, which play important roles in plant growth.
it effects the statues especially those which are made up of limeston......



I hope my answer helped y
obviously thanks alot but if u dont mind i hav more doubts can u or the community will hellp me for my mocks

 

[John Sailmen]

Hey, does anyone have the enterprise October November paper 1. Could you please give it to me. It's the year 2013 only. Thanks in advance.

 

[Ayub259]

I need help with a paper 1 Biology question:
-Which pollutant gas is produced by the decomposition of vegetation?
A carbon monoxide
B methane
C nitrogen oxide
D sulfur dioxide
I know the answer is B, but how is the decomposition of vegetation related to methane production? I never read about it in my textbook..
Thanks in advance!

 

[Awesome12]

I need help with a paper 1 Biology question:
-Which pollutant gas is produced by the decomposition of vegetation?
A carbon monoxide
B methane
C nitrogen oxide
D sulfur dioxide
I know the answer is B, but how is the decomposition of vegetation related to methane production? I never read about it in my textbook..
Thanks in advance!

have u ever heard of biogas? or gas produced for local use by using cow dungs. their combustion release methane

 

[loseroftheyear]

Physics
how do you draw a normal on a curved surface?
What does gamma ray do?
how can i draw wavefront from deep to shallow water

 

[Awesome12]

Physics
how do you draw a normal on a curved surface?
What does gamma ray do?
how can i draw wavefront from deep to shallow water

ans 1. take ur scale and allign any mark of it (eg. 1 cm), such that the line touches the curved surface
like this



Ans. 2 what do u mean 'what do they do' u shud be more specific

Ans. 3 a deep region is LESS DENSE than a shallow region (ie. shallower region is MORE DENSE)
u may have studied that when light passes from a less dense to a denser medium, it speed, and wavelength decreases, but the frequency remains constant
as a result, u might be given the wavefronts for the deep region, and all u have to do is make wavefronts with a smaller wavelength for the shallow region

 

[Awesome12]

need answer fast
View attachment 36935

 

[Sariya Khan]

increase their cross sectional area

thanks..!

 

[Awesome12]

thanks..!

np

 

[Ayub259]

"Suggest why alkanes burn with a non-smoky flame but alkenes burn with a smoky flame"? A little help please.

 

[Awesome12]

"Suggest why alkanes burn with a non-smoky flame but alkenes burn with a smoky flame"? A little help please.

when completely combusted, alkenes burn to produce less soot as compared to alkanes
also alkenes have strained double carbon carbon bond and so more energy is released when it burns

 

[Ayub259]

when completely combusted, alkenes burn to produce less soot as compared to alkanes
also alkenes have strained double carbon carbon bond and so more energy is released when it burns

Thanks!!!

 

[Usman Abdul Jabbar]

Hi guys. I wanted to ask that do I have to show my working in the IGCSE Physics Paper 1 Multiple Choice Paper. (you know like how I got the answer to them?)

Any help will be warmly appreciated.

THANKS

 

[Awesome12]

Hi guys. I wanted to ask that do I have to show my working in the IGCSE Physics Paper 1 Multiple Choice Paper. (you know like how I got the answer to them?)

Any help will be warmly appreciated.

THANKS

no
they only take the answer sheet where u shade in the answers

 

[John Sailmen]

Hey, did the enterprise paper of 2013 winter come out anybody. If it did and u see it, please can you give it to me. I really need it. Thanks in advance.

 

[Ayub259]

A question here. When does Xtremepapers start uploading all the 2013 past papers for IGCSE onto the site? I thought they'd be uploaded by now..

 

[Basil.J]

U just need to write 5 points but a liitle bit explaining bt nt so long

Thanks

 

[Basil.J]

bro... mostly you have to write points rather explanations but some times explanations is needed.!!! it depends on the question ... this is what i did last here during igcse and got distinction..!!!

Thanks

 

[Usman Abdul Jabbar]

Hi guys may anyone give me a guide on how to complete this. Please anyone or any easy way to complete these.