THE PERIODIC TABLE

     By the middle of the 19^th century, a great number of chemical elements had been discovered and scientists needed a more precise way to classify them. As new elements continued to be discovered, scientists observed that some elements had similar properties, such as chlorine, bromine and iodine or calcium, strontium and barium.

     In 1817, J.Döbereiner revealed the similarities between the properties of certain groups of three elements, with a gradual variation of these properties from the first element to the last one. These groups of three elements were called triads. To classify them, Döbereiner explained that the average atomic weight of the weights of the extreme elements, is like the element in the middle of the triad.

     Later, in 1864, J.A.R. Newlands listed the elements increasing their atomic weight. He noticed that similar physical and chemical properties recur at intervals of eight and he grouped known elements with similar properties into groups of eight. He compared this grouping to octaves in music. Initially, his work was not accepted by the scientific community, but was later recognised as the first attempt to classify the elements.

     In 1869, D. Mendeleev and L. Meyer independently published a classification of the elements considering the increase of the atomic mass of the elements and grouping elements together according to their properties. This classification presented several limitations which were improved by H. Moseley in 1913. The Moseley table orders the element by their atomic number (Z), that is, using the number of protons of the elements. Moreover, the position of each element in the periodic table can be related to the characteristics of the atom’s shell. The chemical elements are arranged into:

-   18 columns, called groups or families: all elements in the same group have an equal number of electrons in their valence shell and therefore they have similar chemical properties.

-      7 horizontal rows, called periods: all elements in the same period have the same number of electron shells.

ACTIVITIES: 

     The following activities are presented in different blocks related to different areas. You can choose which area or activity you prefer working on or, you can choose another area for your research. Make a little report with the information you consider relevant and give your opinion about it. Enjoy it!

Focus on English!  Look for the idioms related to the word “table”.

Physics and chemistry:

1. Interactive Periodic Table

You can play and learn with this interactive periodic table and discover the hidden information behind the elements. You can learn more about the uses of each element, It´s up to you! (Element Uses)

2. Build an atom

In this simulation, you can build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!

3. Isotopes and atomic mass

Use the simulation to learn about isotopes and how abundance relates to the average atomic mass of an element.

4. Radioactive elements: search information about one or more radioactive elements and their uses in our society.

Maths:

5. Choose the element you prefer to work with and look for the information you need to calculate their average atomic mass (weighted mass).

Medicine:

6. Look for the elements used in different kind of therapies like radiotherapy or chemotherapy.
7. Search for information about which elements are used to make medicines, implants, pharmacology…

Biology:

8. Search the necessary elements for a balanced diet.
9. Look for which elements are relevant for animals and plants and make a table with their similarities and differences.
10. Look for which elements are dangerous for life (animals and plants).
11. Which animals have poisoned protection? Which elements are involved in it?

Geology:

12. Look for elements used in jewellery.
13. Search which elements are relevant in geology, or which are the most abundant elements in Earth.

History:

14. Which elements are used to know the age of the different discoveries in archaeology?

Technology/Engineering:

15. Look for the elements needed for doing a watch, laptop, iPhone, tablet, battery, etc.
16. Which elements are useful in aeronautics, vehicles, buildings, energy systems…?

Music/Art:

17. Look for information about which elements are the best for doing different instruments like a flute, saxophone, etc.
18. Search information about the elements used for doing different colours or for the conservation of the artwork, etc.

At home or in your school: 

19. Look for the elements we use in our daily life or we have around us at home or at school. 

Sources of information:

- Physics and chemistry. 3th Secondary Education. Grupo Anaya, 2015.

- The periodic table of the elements, in pictures and words. Keith Enevoldsen  http://elements.wlonk.com/ElementsTable.htm

- Periodic table in https://en.wikipedia.org/wiki/Periodic_table

- Phet Simulations in https://phet.colorado.edu/