TYS 'O' LVL chem questions

• gunner77

  14 Oct 08, 22:48

  2006 - 5b

  both hydrogen and helium have been used to fill balloons. Hydrogn is more reactive and less safe to use.

  use the electronic structure of the atoms of these two elements to explain why hydrogen is more reactive than helium. (3marks)

  2006 - 5c

  Aluminium is an element in group 3 of the periodic table. Use your knowledge of electronic structure to explain why aluminium is a metal. (3marks)

  anyone can help me?

• crimsontactics

  14 Oct 08, 22:51

  Helium is a noble gas, noble gas have no charge and are stable and unreactive

  Hydrogen has a plus one charge, it needs one more electron to achieve the noble gas structure, thus it is more reactive than helium as there are transfer of electrons happening.

• crimsontactics

  14 Oct 08, 22:54

  Originally posted by gunner77:

  2006 - 5b

  both hydrogen and helium have been used to fill balloons. Hydrogn is more reactive and less safe to use.

  use the electronic structure of the atoms of these two elements to explain why hydrogen is more reactive than helium. (3marks)

  2006 - 5c

  Aluminium is an element in group 3 of the periodic table. Use your knowledge of electronic structure to explain why aluminium is a metal. (3marks)

  anyone can help me?

  It has three valence electrons, causing it to give out rather than take in electron to form an ion.

• Maith

  14 Oct 08, 22:55

  aluminium has 3 outer electrons thus it will give away 3 electrons to form a ionic bond with a non-metal. And metals are always the one that gives away electrons..

  lol,2 more days to practical! ):

• gunner77

  14 Oct 08, 23:01

  Originally posted by crimsontactics:

  It has three valence electrons, causing it to give out rather than take in electron to form an ion.

  
  but like tat answer will give u full 3 marks?

• Ahm97sic

  14 Oct 08, 23:05

  Hi Gunner,

  tin tin is online, perhaps you can ask him now.

  Regards,

  ahm97sic

• gunner77

  14 Oct 08, 23:06

  

  anybody can help me answer can liao

• tinuviel07

  14 Oct 08, 23:23

  gunner dowan me liao... and tin tin is a she thanks

• gunner77

  14 Oct 08, 23:26

  Originally posted by tinuviel07:

  gunner dowan me liao... and tin tin is a she thanks

  
  HUH !!

  U ARE A GAL !  wah seh i thought u boy

  no la i want u

  pls help me :(

• tinuviel07

  14 Oct 08, 23:33

  lol.. =.="

  both hydrogen and helium have been used to fill balloons. Hydrogn is more reactive and less safe to use.

  use the electronic structure of the atoms of these two elements to explain why hydrogen is more reactive than helium. (3marks)

  When elements have stable electronic configurations, they are very unreactive as they have a fully-filled outer shell. Hydrogen has electronic configuration 1 and hence it will undergo bonding with another element to form a compound to achieve stable electronic configuration.
  

  Helium on the other hand, has 2 electrons in the outershell, hence its outershell is completely filled, making it very stable and unreactive.

   

• gunner77

  14 Oct 08, 23:35

  then the part B leh

• crimsontactics

  14 Oct 08, 23:36

  Originally posted by tinuviel07:

  lol.. =.="

  both hydrogen and helium have been used to fill balloons. Hydrogn is more reactive and less safe to use.

  use the electronic structure of the atoms of these two elements to explain why hydrogen is more reactive than helium. (3marks)

  When elements have stable electronic configurations, they are very unreactive as they have a fully-filled outer shell. Hydrogen has electronic configuration 1 and hence it will undergo bonding with another element to form a compound to achieve stable electronic configuration.
  

  Helium on the other hand, has 2 electrons in the outershell, hence its outershell is completely filled, making it very stable and unreactive.

   

  Helium on the other hand, has 2 electrons in the outershell, hence its outershell is completely filled, making it very stable and unreactive.

  I think it would much easiler to just remember helium as a noble gas. Noble gases are unreactive and stable.

• tinuviel07

  14 Oct 08, 23:38

  yes it's true that noble gases are unreactive but the question asked why.. or did i read it wrongly?

• crimsontactics

  14 Oct 08, 23:38

  Originally posted by gunner77:

  
  but like tat answer will give u full 3 marks?

  Hmm, i think its this way,

  1. Al has 3 valence electrons

  2. Causing it to give electrons rather than take

  3. To form a positive ion ( by maith )

• crimsontactics

  14 Oct 08, 23:40

  Originally posted by tinuviel07:

  yes it's true that noble gases are unreactive but the question asked why.. or did i read it wrongly?

  Your answer is correct. It's just that i fill that by writing the noble gases thing will be more time-saving as it requires lesser words.

• gunner77

  14 Oct 08, 23:40

  ohh thanks everyone !

   

  tin tin help me with maths

  i post the question liao thanks very very much!

• gunner77

  15 Oct 08, 00:14

  solid D is a speckled green and white.

  the green particles dissolve in water but the white particles do not.

  is solid D a compound, element or mixture?

   

   

  the answer is mixture but i dont understand why?

  there is only 2 particles, shouldn't it be compound?

• tinuviel07

  15 Oct 08, 00:17

  i put it crudely ok? haha..

  if the whole thing is compound, the whole thing should dissolve in water or the whole thing should not dissolve in water ma.. means there's two separate parts behaving differently in water.. means mixture lor.. cause two separate things together..

  if like say you put NaCl in water.. the whole thing dissolve right? won't be one part dissolve one part don't..

  but if you have say NaCl and BaSO4 (insoluble in water), then the NaCl will dissolve but the BaSO4 won't and this is a mixture cause they behave differently

• gunner77

  15 Oct 08, 00:23

  ohh !

  icic. hmm now i understand.

  thanks! one more question.

  an ore contains 10% by mass of the minera, wolframite

  wolframite contains tungsten,W and has the formula (FeMn)WO4

  (i) calculate the mass of wolframite in 10 tonnes if the ore.

  (II) calculate the mass of tungstenin 10 tonnes of the ore.

  [ relative atomic masses: A; O, 16; Mn, 55; Fe 56; W, 184 ]

• tinuviel07

  15 Oct 08, 00:27

  Originally posted by gunner77:

  ohh !

  icic. hmm now i understand.

  thanks! one more question.

  an ore contains 10% by mass of the minera, wolframite

  wolframite contains tungsten,W and has the formula (FeMn)WO4

  (i) calculate the mass of wolframite in 10 tonnes if the ore.

  (II) calculate the mass of tungstenin 10 tonnes of the ore.

  [ relative atomic masses: A; O, 16; Mn, 55; Fe 56; W, 184 ]

  who the hell give such a name.. grr

  Mass of wolf = 10% x 10tonnes = XXX

  Mass of tungsten = (Ar of Tungsten / Mr of wolf) x ( XXX )

  remember to change tonnes to grams

   

   

• gunner77

  15 Oct 08, 00:31

  ohh !!

  ok thanks alot! more no liao

  thank cute

• tinuviel07

  15 Oct 08, 00:32

  okie.. np

• gunner77

  15 Oct 08, 00:33

  u may go to bed now

  sleep well.

  i need to repair the image of u in my mind.

  i need to change the gender.

• tinuviel07

  15 Oct 08, 00:34

  err okay.. don't repair too jialat-ly

• gunner77

  15 Oct 08, 00:35

  Originally posted by tinuviel07:

  who the hell give such a name.. grr

  Mass of wolf = 10% x 10tonnes = XXX

  Mass of tungsten = (Ar of Tungsten / Mr of wolf) x ( XXX )

  remember to change tonnes to grams

   

   

  
  wait wait

  tin tin i wan to ask u

  the mass of tungsten shouldn't it be ( ar of tungsten/mr of wolf) x 100% ?