Science Homework Help

For this assignment I am to conduct a hazardous chemical briefing/presentation at my work: This presentation is on

silica (in its crystalline form) which causes silicosis if inhaled which is a major hazard in the construction industry. I am not sure if this would be considered a hazardous chemical or if it will fit for the questions I must answer during my presentation. If it is not, I will chose something else so please let me know either way.

Note: I have already completed questions 1-5 to the best of my ability. I’m looking to verify my work and make sure I have done this assignment correctly. As for question #6 I am completely lost, any help with this question would be greatly appreciated.

1.) Please explain and show the molecular structure of silica or Silicon dioxide: (I’m looking for the natural crystalline form found in construction, that causes silicosis).

and or, the element Silicon and their relationship if that is easier or different.

2.) Identify the type of molecule for silica or Silicon dioxide? (Ionic or Covalent)

3.) Identification of whether the molecule is polar or non-polar?

4.)Relation of its chemical behavior to its structure?

5.) If it is a large molecule, the identification of one central atom and its VSEPR shape?

6.) Identification of at least three bonds within the molecule and their bond lengths and enthalpies?