Scientific Method in Real Cases

Scientific Method is widely used for real cases. Some of its application can seem weird for us. Such is the case of investigating the causes for air crashes. However, going over those terrific tragedies has proven essential to help new victims and stop the toll increasing. 
This video may seem tragic for you, but it will help you understand the vital importance of the scientific method for skillfull investigators in order to clarify such crashes. Watch the film and answer these questions:

1. What kind of plane suffers the tragedy?
2. How many people, in total, were travelling inside?
3. When they describe several passengers they focused on two women and a man: Why were they travelling?
4. Why was the flight delayed?
5. How long did it take to the plane to be doomed?
6. Who saw the accident first?
7. Which were the two initial hypothesis to explain the accident?
8. What did they have to study to check this hypothesis?
9. Tell at least two experiments they performed to work out the real cause for the accident?
10. Explain the conclusions of the investigation?
11. Did the investigation lead to any change in planes to help new similar tragedies? Tell examples 

3ESO Structure of Matter.

1. For the Species   
   
    indicate the number of electrons,
   
   neutron, protons.
2. We have 3 different atoms: a)Z=2; b)Z=7; c)Z=11. Write their electrónic configuration, period, Group, aggregation state, stable ions, stoichiometry of the compound b-c
3. Tell which type of radioactive emmission: a)is formed by electrons b)is most penetrating c)is formed by heaviest particles

4ESO Stoichiometry as a whole

1. When 200 g of NaHCO3 95% react with HCl 0.5M they produce Sodium chloride, water and a gas which provoques global warming  is released. a) Write the chemical equation  (balance it). b)Determine the volume of HCL 0.5M you need c)Determine the volume of gas measured at 20°C and 0.9 atm.
2. In a blast furnace, Iron is reduced from Fe2O3 to Fe (steel in fact) with graphite (C), which turns into CO2. Write the chemical equation. Determine the mass of graphite they need to get a kg of steel, and the volume of CO2 measured at 500°C and 2.5 atm.

Data: Pm Cl:35.5; Na 23; C 12; O 16; H 1 g/mol R=0.082 atm•l/Kmol