lunes, 16 de enero de 2017

A modern version of the gold foil experiment

A modern version of one of the most important experiment in the history of science.

Watch the video and answer the questions

1.- Who made this experiment more than one hundred years ago?
2.- Which kind of particles are used in this experiment?
3.- Why some of the particles pass straight ahead but others are deflected?
4.- What does 1.5 microns refers to?
5.- What does the bell sound represent?
6.- Mention two differences between the original experiment and the modern one.
7.- How many particles per second are detected by each detector?
8.- What conclusion can we make from the results of this experiment?
a) J. J. Thomson was right.
b) Atoms are mostly empty space.
c) Atoms are rigid spheres.
d) None of above.
 9.- What happen to the particles passing closer the nucleus?

domingo, 15 de enero de 2017

Chemical equations calculations. Exercise 6.

Alba Muñoz 4º B

Concentration. Exercise 8.

We need to prepare 150 ml of a 20 g/L solution of iodine. How much iodine and water do we need? Explain how to prepare this solution in the lab.

Enrique Borrego 3º A

Concentration. Exercise 10.

When 33g of sugar are dissolved in 198 g of water we get 0,22 liters of solution. Calculate the mass concentration (g/L) and the percent of mass of the solution.

María Ordóñez 3º A

Concentration. Exercise 6.

A solution has been prepared with 30 g of sugar solved in water till we get 200 ml of solution. Which is its mass concentration of sugar in g/L?

Mª Dolores Godino 3º A

Concentration. Exercise 7.

We weight 5 g of sodium chloride and water is added till we have 250 ml of solution. What mass concentration (g/L) of sodium chloride we get?

María Benitez 3º A