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POST YOUR BIO AND CHEM PAPER 1 DOUBT HERE !!!!

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Atom X has 8 more electrons than atom Y.
Student 1 says they are in the same group.
Student 2 says they are unreactive.
Which students can be correct?
student 1 student 2
A  yes yes
B  yes no
C  no yes
D  no no
I don't get the question so that i will solve it
Alright ..
lets take any element fron grp 0 according to student 2
eg : I take Argon , question says that Atom X (eg: Argon) has 8 more elctrons than Atom Y
The proton number of Argon is 18 which is equal to the number of electron
So, subtract 18-8=10 and check in the periodic table for the element with the proton number 10
Neon has the proton number 10
Now ,Neon and argon are unreactive? Yes! Are they in the same group? Yes!
So your answer is A :)
 
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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.
thank you sooo much u helped a lot!!
 
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Alright ..
lets take any element fron grp 0 according to student 2
eg : I take Argon , question says that Atom X (eg: Argon) has 8 more elctrons than Atom Y
The proton number of Argon is 18 which is equal to the number of electron
So, subtract 18-8=10 and check in the periodic table for the element with the proton number 10
Neon has the proton number 10
Now ,Neon and argon are unreactive? Yes! Are they in the same group? Yes!
So your answer is A :)

I think the answer is B, because they never said that it is a noble gas, so let's take for example as element X instead of argon, sodium, sodium's proton number is 11, and they say that element Y has 8 more electrons than element X, so 11+8 = 19, 19 is the proton number of Potassium. So it is not necessarily a noble gas, it must be in the same group but not necessarily group 8/0 :) . Answer : B.
 
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hey guys i have a hard chem question, http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w04_qp_1.pdf

question 11

answer is A

how r we supposed to know that?!! thank youuuuuuu
if copper is heated, mass increases because it becomes copper oxide. if copper carbonate is heated, mass will reduce because carbondioxide is formed. if copper oxide is heated, it will decompose and so mass will reduce. if hydrated copper sulphate is heated, it will become dehydrated, and so mass will reduce. so the answer is A. :D
 
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hey guys i have a hard chem question, http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w04_qp_1.pdf

question 11

answer is A

how r we supposed to know that?!! thank youuuuuuu
D will become dehydrated so there will be a decrease in mass
C will melt so na change in mass
B will decompose n its mass will decrease as carbondioxide will escape
A when heated in air will form Copper oxide so there will be an increase in mass
The table shows an increase in mass after heating so it's A
 
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D will become dehydrated so there will be a decrease in mass
C will decompose n its mass will decrease as carbondioxide will escape
B will melt so na change in mass
A when heated in air will form Copper oxide so there will be an increase in mass
The table shows an increase in mass after heating so it's A
B doesn't melt. it decomposes
 
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hey guys i have a hard chem question, http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w04_qp_1.pdf

question 11

answer is A

how r we supposed to know that?!! thank youuuuuuu

I think because B, C and D are all invalid for the answer because they will lose mass since copper (II) oxide will decompose I think to copper and oxygen, and the oxygen will be lost so the mass will decrease. Copper (II) carbonate when heated forms copper oxide and carbon dioxide, carbon dioxide escapes, decreasing the mass. As for D, which is hydrated copper (II) sulfate, when heated, water evaporates, so the mass decreased. In the question the mass increases, so B, C, D are all invalid. A is the correct answer because when copper is heated, the oxygen in the air combines with the copper forming copper oxide, increasing the mass. Wheew hope this helped :D
 
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I think the answer is B, because they never said that it is a noble gas, so let's take for example as element X instead of argon, sodium, sodium's proton number is 11, and they say that element Y has 8 more electrons than element X, so 11+8 = 19, 19 is the proton number of Potassium. So it is not necessarily a noble gas, it must be in the same group but not necessarily group 8/0 :) . Answer : B.
This is the question she asked:
Atom X has 8 more electrons than atom Y.
Student 1 says they are in the same group.
Student 2 says they are unreactive. <--- They din say it's a noble gas but they said its unreactive
Which students can be correct?
 
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This is the question she asked:
Atom X has 8 more electrons than atom Y.
Student 1 says they are in the same group.
Student 2 says they are unreactive. <--- They din say it's a noble gas but they said its unreactive
Which students can be correct?

Yes, unreactive metals are noble gases. But as I said before, If you read throughout the answer I gave and the example, you would see that it is not necessary a noble gas, it could be any group, but the two elements must be in the same group.
 
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I think because B, C and D are all invalid for the answer because they will lose mass since copper (II) oxide will decompose I think to copper and oxygen, and the oxygen will be lost so the mass will decrease. Copper (II) carbonate when heated forms copper oxide and carbon dioxide, carbon dioxide escapes, decreasing the mass. As for D, which is hydrated copper (II) sulfate, when heated, water evaporates, so the mass decreased. In the question the mass increases, so B, C, D are all invalid. A is the correct answer because when copper is heated, the oxygen in the air combines with the copper forming copper oxide, increasing the mass. Wheew hope this helped :D


thank youuuu but why does copper oxide decompose? its not a nitrate or a carbonate or a hydroxide ( these are the only ones that we learnt at school)
 
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if copper is heated, mass increases because it becomes copper oxide. if copper carbonate is heated, mass will reduce because carbondioxide is formed. if copper oxide is heated, it will decompose and so mass will reduce. if hydrated copper sulphate is heated, it will become dehydrated, and so mass will reduce. so the answer is A. :D

thank youuuu but why does copper oxide decompose? its not a nitrate or a carbonate or a hydroxide ( these are the only ones that we learnt at school)
 
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It's an oxide, and oxides do decompose upon heat, also copper is a very unreactive metal ( down in the reactivity series ) meaning its oxide decomposes more easily than the more reactive metals.
 
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D will become dehydrated so there will be a decrease in mass
C will decompose n its mass will decrease as carbondioxide will escape
B will melt so na change in mass
A when heated in air will form Copper oxide so there will be an increase in mass
The table shows an increase in mass after heating so it's A

thank youuuu but why does copper oxide decompose? its not a nitrate or a carbonate or a hydroxide ( these are the only ones that we learnt at school)
 
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