Silicon is an element in Group IV of the Periodic Table.

1. (a)One of the isotopes of silicon is: 30 14 Si Deduce the number of electrons, neutrons and protons in one atom of this isotope of silicon. number of electrons .................................................................................................................... number of neutrons .................................................................................................................... number of protons .................................................................................................................... [3][3]
2. (b)Silicon reacts with nitrogen when heated to produce silicon nitride, Si3N4. Construct the equation for this reaction.[1]
3. (c)The structure of silicon dioxide is shown. silicon atom oxygen atom [Figure: Ball-and-stick model of silicon dioxide lattice structure, with black spheres for silicon and white spheres for oxygen]
4. (c)(i)Describe two similarities in the structures of silicon dioxide and diamond. 1 ..................................................................................................................................................... 2 ..................................................................................................................................................... [2][2]
5. (c)(ii)Explain why silicon dioxide has a high melting point.[2]
6. (d)The structure of a compound of silicon is shown. H HH O HH H–C–C—Si—C–C–H HH O HH H Deduce the molecular formula of this compound.[1]
7. (e)Draw a 'dot-and-cross' diagram for a silicon(IV) chloride molecule, SiCl4. Only include the outer shell electrons.[1]

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