Chemistry Help HERE ONLY !!

[godfather93]

germanium is a metalloid and a semiconductor. it has a similar sturcture as that of silicon and it's bonding structure is tetrahedral like carbon.
only when germanium is heated that the electrons of the germanium atoms can become delocalised. but in this case nothing about heat being applied is being said.

[Shogun]

Questions :

1) wha are the 2 uses of the 5 halogen atoms ??
2) explain by giving its structure why diamond is so hard ?? [4]
3) explain the structure of Diamond ??
4) describe the structure of germanium ?

alright; use of chlorine: uised to make PVC, used in making hose hold beach
          use of bromine, used in photography, used to make medicine
          use in flourine: used to make toothpste, used to add in water for dental care
          use idoine, used in the treatment of thyroid gland, used to make medicine
          use os astatine, we dont have uses to learn in syllabus, but is used in making medicine, and is used to treat thyroid gland.

2) each carbon atom is held in its place by 4 strong covalent bonds. so diamond is very hard and can be used as jewelry or in drilling or cutting equipment.

3)diamond is tetrahedron in shape. and 4 carbon atoms is covalently bonded with 4 other carbon atom.

4)germanium would have the same structure as carbon and silicon, which would be tetrahedron,
so yes godfather what u said abou germanium is correct, and lil wayne this answer is correct.

and silicon has the same structure and properties as diamond, except the hardness property.
hope this helped nanavil. any othe questions u have plz do ask me

[SGVaibhav]

Sulphur reacts violently with magnesium to form the ionic compound magnesium
sulphide. Draw a diagram that shows the arrangement of the valency electrons in this
compound.
Use O to represent an electron from a magnesium atom.
Use X to represent an electron from a sulphur atom. [3]


Please do this

[Phosu]

could someone plz send me the marking schemes from june 1997 to nov 2000

[Shogun]

Sulphur reacts violently with magnesium to form the ionic compound magnesium
sulphide. Draw a diagram that shows the arrangement of the valency electrons in this
compound.
Use O to represent an electron from a magnesium atom.
Use X to represent an electron from a sulphur atom. [3]


Please do this

ill draw this in paint and give it to u..

[Ghost Of Highbury]

plz find it attached

Mg ? Mg2+ + 2 e-
S + 2e- ? S2-[

[tnzgurl]

can someone help me understand the difference between evaporation and crystallization? and when you would use each one ?

[Shogun]

its ionic bonding

and it should Mg⁺² not -2
sorry it was a mistake.

[Nanavel]

how do you know what is the suitable reagents for certain reactions ??

If they ask me do describe the structure of Diamond >>> I can either say :   " It has tetrahydral shap with four carbon atoms convalently bonded to other four carbon forming a gaint marcomolecular shap "
                                                                                                                                                                                          OR
                                                                                                     " It has tetrahydral structure with four oxygen atoms covalently bonded with a single atom of Silion forming a gaint marcomolecular shap "

[Shogun]

can someone help me understand the difference between evaporation and crystallization? and when you would use each one ?

evaoration is heating water and changin it to gas, crystallysation is when u evaporate until crystallisation poin(when crystals starts to form) then cool slowly.

[Ghost Of Highbury]

evaporation - a process occuring at the surface if a liquid invloving the change of state if a kiquid into vapour
at a temperature below the boiling point

crystallisation - salt is obtained from sea water on vast scale through crystallisation, this is done by using the heat of the sun to evaporate the water to leave a saturated solution of salt. after saturation, the salt begins to crystallise. it is actually heating followed by quick cooling.

[Shogun]

how do you know what is the suitable reagents for certain reactions ??

If they ask me do describe the structure of Diamond >>> I can either say :   " It has tetrahydral shap with four carbon atoms convalently bonded to other four carbon forming a gaint marcomolecular shap "
                                                                                                                                                                                          OR
                                                                                                     " It has tetrahydral structure with four oxygen atoms covalently bonded with a single atom of Silion forming a gaint marcomolecular shap "

tht u have to mug up the reactions' reagent or use common sense, cuz its just impossible to tell which reagent to use or which reagent is for which reactions, in this post cuz thier are a million ef em and differnt type of it use different rreagents, so to solve tese problem, understand the concept of making salts and the concept of testing alcohols and alkenes and cations and anions, understand tht concept, for eg: how they from precipitate, why they change colour, etc. tht way u will know which reagent to use and when.

and the structure, use the first one, seems to be more acceptable and easy, appropriate.

oh yea evaporation can happen at any temperature at surface of liqiud, not as boiling point which occurs at a fixed temp called boiling point.

[Shogun]

adi, how do i put pics on posts...

[Ghost Of Highbury]

u gotta click on reply --> additional options--> attach --> choose file --  attach the image --> post
the image will also appear with the attachment
 

[SGVaibhav]

plz find it attached

Mg ? Mg2+ + 2 e-
S + 2e- ? S2-[

THANKS A LOT
 yeaahhh
but i got one more question 

Bromine reacts with phosphorus to form phosphorus tribromide.
Draw a diagram showing the arrangement of the valency electrons in one molecule of
this covalent compound. The electron distribution of bromine is:
2 + 8 + 18 + 7.
Use x to represent an electron from phosphorus.
Use o to represent an electron from bromine.

very over here