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fishcook

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Lost_Life said:
40 At each stage in a food chain, energy is lost.
What is a result of this?
A All living organisms respire.
B Food chains always begin with green plants.
C Plants are called producers and animals consumers.
D There are very few food chains with more than five organisms

why is the answer D not A....???
Click to expand...
you have to read the Q properly it says 'what is the result of this'. so it means the because energy is lost at every organism a food chain will be limited to 5 or less organisms. i read it in the examiner report.
 
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fishcook

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Skynox said:
It's definetly neutralization since neutralization is the reaction between an acid and an alkali where the alkali destroys the acidity of the acid by accepting its hydrogen ion forming salt and water...



Okay for that number 8 he is asking about a solid non-metal ,all non metals whatever there state is don't conduct electricity so it is either A,B,or C..You are left with melting point and boiling point..To know the state of the element at room temperatures use 20 C and trying putting it between the melting and boiling point
for example
A
MP:-210 BP:-183
Defintly the 20 goes after both so it is a gas at room temperature.
For C,
MP:119 BP:149
The 20 goes before both so it is a solid
Okay for that number 15
Classifying salts as acidic,neutral,basic
A neutral

Neutral salts are formed from the reaction between a strong acid and strong base like HNO3,and KOH.
Click to expand...
why does the ms say A? :s
 
Tekno-M

Tekno-M

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GorgeousEyes said:
Why the answe is B?
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Because every molecule of hydrogen has to hydrogen atoms, each of relative atomic mass 1, so the relative atomic mass of a molecule of hydrogen is 2, so 2x8 = 16 which is the relative atomic mass of an oxygen atom. So the relative atomic mass of 1 atom of oxygen = the relative atomic mass of 8 molecules of hydrogen
 
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